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N-2 - USD ($) |  |  | 3 Months Ended | 12 Months Ended |
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Feb. 21, 2025 | Jan. 31, 2025 | Jan. 31, 2025 | Oct. 31, 2024 | Jul. 31, 2024 | Apr. 30, 2024 | Jan. 31, 2024 | Oct. 31, 2023 | Jul. 31, 2023 | Apr. 30, 2023 | Jan. 31, 2023 | Oct. 31, 2024 | Oct. 31, 2023 | Oct. 31, 2022 | Oct. 31, 2021 | Oct. 31, 2020 | Oct. 31, 2019 | Oct. 31, 2018 | Oct. 31, 2017 | Oct. 31, 2016 | Oct. 31, 2015 | Oct. 31, 2014
Cover [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Entity Central Index Key |  | 0001171471 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amendment Flag |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Entity Inv Company Type |  | N-2 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Securities Act File Number |  | 333-000000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Investment Company Act File Number |  | 811-21080 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Document Type |  | N-2ASR |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Document Registration Statement |  | true |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Pre-Effective Amendment |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Post-Effective Amendment |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Investment Company Act Registration |  | true |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Investment Company Registration Amendment |  | true |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Investment Company Registration Amendment Number |  | 39 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Entity Registrant Name |  | CALAMOS CONVERTIBLE OPPORTUNITIES AND INCOME FUND |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Entity Address, Address Line One |  | 2020 Calamos Court |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Entity Address, City or Town |  | Naperville |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Entity Address, State or Province |  | IL |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Entity Address, Postal Zip Code |  | 60563 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
City Area Code |  | 630 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Local Phone Number |  | 245-7200 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Approximate Date of Commencement of Proposed Sale to Public |  | From time to time after the effective date of this Registration Statement. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividend or Interest Reinvestment Plan Only |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Delayed or Continuous Offering |  | true |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Primary Shelf [Flag] |  | true |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Effective Upon Filing, 462(e) |  | true |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Additional Securities Effective, 413(b) |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Effective when Declared, Section 8(c) |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
New Effective Date for Previous Filing |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Additional Securities. 462(b) |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
No Substantive Changes, 462(c) |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Exhibits Only, 462(d) |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Registered Closed-End Fund [Flag] |  | true |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Development Company [Flag] |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interval Fund [Flag] |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Primary Shelf Qualified [Flag] |  | true |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Entity Well-known Seasoned Issuer |  | Yes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Entity Emerging Growth Company |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
New CEF or BDC Registrant [Flag] |  | false |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fee Table [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shareholder Transaction Expenses [Table Text Block] |  |
Shareholder Transaction Expenses |  |  |
Sales Load (as a percentage of offering price) |  |  | — | (1)
Offering Expenses Borne by the Fund (as a percentage of offering price) |  |  | — | (1)
Dividend Reinvestment Plan Fees (per sales transaction fee)(2) |  | $ | 15.00 |
(1) If the securities to which this prospectus relates are sold to or through underwriters, the prospectus supplement will set forth any applicable sales load and the estimated offering expenses borne by us. (2) Shareholders will pay a $15.00 transaction fee plus a $0.02 per share brokerage charge if they direct the Plan Agent (as defined below) to sell common shares held in a Plan account. In addition, each participant will pay a pro rata share of brokerage commissions incurred with respect to the Plan Agent's open-market purchases in connection with the reinvestment of dividends or distributions. If a participant elects to have the Plan Agent sell part or all of his or her common shares and remit the proceeds, such participant will be charged his or her pro rata share of brokerage commissions on the shares sold. See "Dividends and Distributions on Common Shares; Automatic Dividend Reinvestment Plan." |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sales Load [Percent] | [1] | 0.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividend Reinvestment and Cash Purchase Fees | [2] | $ 15 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Transaction Expenses [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Transaction Expenses [Percent] | [1] | 0.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Annual Expenses [Table Text Block] |  |
Annual Expenses |  | Percentage of Average Net Assets Attributable to Common Shareholders |
Management Fee(3) |  |  | 1.26 | %
Interest Payments on Borrowed Funds(4) |  |  | 2.18 | %
Preferred Stock Dividend Payments(5) |  |  | 0.70 | %
Other Expenses(6) |  |  | 0.09 | %
Total Annual Expenses |  |  | 4.23 | %
(3) The Fund pays Calamos an annual management fee, payable monthly in arrears, for its investment management services in an amount equal to 0.80% of the Fund's average weekly managed assets. In accordance with the requirements of the Commission, the table above shows the Fund's management fee as a percentage of average net assets attributable to common shareholders. By showing the management fee as a percentage of net assets, the management fee is not expressed as a percentage of all of the assets the Fund intends to invest. For purposes of the table, the management fee has been converted to 1.26% of the Fund's average weekly net assets as of January 31, 2025 by dividing the total dollar amount of the management fee by the Fund's average weekly net assets (managed assets less outstanding leverage). (4) Reflects interest expense paid on $254 million in average borrowings under the SSB Agreement, plus $61 million in additional average structural leverage related to certain securities lending programs, as described under "Leverage." (5) Reflects estimated dividend expense on $133 million aggregate liquidation preference of mandatory redeemable preferred shares outstanding. See "Leverage." (6) "Other Expenses" are based on estimated amounts for the Fund's current fiscal year. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management Fees [Percent] | [3] | 1.26% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest Expenses on Borrowings [Percent] | [4] | 2.18% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividend Expenses on Preferred Shares [Percent] | [5] | 0.70% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Annual Expenses [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Annual Expenses [Percent] | [6] | 0.09% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total Annual Expenses [Percent] |  | 4.23% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Expense Example [Table Text Block] |  | Example: The following example illustrates the expenses that common shareholders would pay on a $1,000 investment in common shares, assuming (1) total annual expenses of 4.23% of net assets attributable to common shareholders; (2) a 5% annual return; and (3) all distributions are reinvested at net asset value:
|  | 1 Year |  |  | 3 Years |  |  | 5 Years |  |  | 10 Years |
Total Expenses Paid by Common Shareholders(7). |  | $ | 42 |  |  | $ | 128 |  |  | $ | 216 |  |  | $ | 441 |
The example should not be considered a representation of future expenses. Actual expenses may be greater or less than those assumed. Moreover, our actual rate of return may be greater or less than the hypothetical 5% return shown in the example. (7) The example does not include sales load or estimated offering costs, which would cause the expenses shown in the example to increase. In connection with an offering of common shares, the applicable prospectus supplement will set forth an example including sales load and estimated offering costs. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Expense Example, Year 01 | [7] | $ 42 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Expense Example, Years 1 to 3 | [7] | 128 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Expense Example, Years 1 to 5 | [7] | 216 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Expense Example, Years 1 to 10 | [7] | $ 441 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Purpose of Fee Table , Note [Text Block] |  | The following table and example contain information about the costs and expenses that common shareholders will bear directly or indirectly. In accordance with Commission requirements, the table below shows our expenses, including interest payments on borrowed funds, and preferred stock dividend payments, as a percentage of our average net assets as of January 31, 2025, and not as a percentage of gross assets or managed assets. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Basis of Transaction Fees, Note [Text Block] |  | as a percentage of offering price |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Expenses, Note [Text Block] |  | "Other Expenses" are based on estimated amounts for the Fund's current fiscal year. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Financial Highlights [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Securities [Table Text Block] |  |
Fiscal Year Ended |  | Total Amount Outstanding |  |  | Asset Coverage |  |  | Liquidating Preference per Preferred Share(c) |  |  | Average Market Value per Preferred Share |  |  | Type of Senior Security
October 31, 2024 |  | $ | 314,650,000 |  |  | $ | 3,835 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2024 |  | $ | 132,750,000 |  |  |  | 227 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2023 |  | $ | 314,400,000 |  |  | $ | 3,563 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2023 |  | $ | 133,000,000 |  |  |  | 211 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2022 |  | $ | 339,400,000 |  |  |  | 3,630 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2022 |  | $ | 133,000,000 |  |  |  | 232 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2021 |  | $ | 399,400,000 |  |  |  | 4,116 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2021 |  | $ | 133,000,000 |  |  |  | 309 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2020 |  | $ | 288,400,000 |  |  |  | 4,431 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2020 |  | $ | 100,000,000 |  |  |  | 319 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2019 |  | $ | 277,400,000 |  |  |  | 4,080 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2019 |  | $ | 100,000,000 |  |  |  | 283 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2018 |  | $ | 288,000,000 |  |  |  | 3,921 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2018 |  | $ | 100,000,000 |  |  |  | 282 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2017 |  | $ | 275,000,000 |  |  |  | 4,265 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2017 |  | $ | 100,000,000 |  |  |  | 293 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2016 |  | $ | 306,000,000 |  |  |  | 3,454 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2015 |  | $ | 353,000,000 |  |  |  | 3,316 | (a) |  |  | - |  |  |  | - |  |  | Loan
(a) Calculated by subtracting the Fund's total liabilities (not including notes payable and MRPS) from the Fund's total assets and dividing this by the amount of notes payable outstanding, and by multiplying the result by 1,000. (b) Calculated by subtracting the Fund's total liabilities (not including MRPS) from the Fund's total assets and dividing this by the number of MRPS outstanding, and by multiplying the result by 25. (c) "Liquidating Preference per Preferred Share" means the amount to which a holder of preferred shares would be entitled upon the liquidation of the Fund in preference to common shareholders, expressed as a dollar amount per preferred share. (d) The MRPS are not listed on any exchange or automated quotation system. The MRPS are considered debt of the issuer; and the liquidation preference approximates fair value. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Securities Amount |  |  |  |  |  |  | $ 759,206,000 |  |  |  |  |  |  |  | $ 672,782,000 |  |  |  |  |  |  |  | $ 759,206,000 |  | $ 672,782,000 |  | $ 759,716,000 | $ 1,111,526,000 | $ 889,577,000 | $ 754,310,000 | $ 741,306,000 | $ 797,968,000 | $ 750,773,000 | $ 817,491,000 |
Senior Securities Coverage per Unit | [8] |  |  |  |  |  | $ 3,835 |  |  |  |  |  |  |  | $ 3,563 |  |  |  |  |  |  |  | $ 3,835 |  | $ 3,563 |  | $ 3,630 | $ 4,116 | $ 4,431 | $ 4,080 | $ 3,921 | $ 4,265 | $ 3,454 | $ 3,316 |
Senior Securities, Note [Text Block] |  | The following table sets forth information regarding the Fund's outstanding bank loans and MRP Shares as of the end of each of the Fund's last ten fiscal years, as applicable. The information in the table shown below comes from the Fund's financial statements for the fiscal year ended October 31, 2024, and each of the prior nine years then ended, all of which have been audited by Deloitte & Touche LLP, the Fund's independent registered public accounting firm.
Fiscal Year Ended |  | Total Amount Outstanding |  |  | Asset Coverage |  |  | Liquidating Preference per Preferred Share(c) |  |  | Average Market Value per Preferred Share |  |  | Type of Senior Security
October 31, 2024 |  | $ | 314,650,000 |  |  | $ | 3,835 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2024 |  | $ | 132,750,000 |  |  |  | 227 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2023 |  | $ | 314,400,000 |  |  | $ | 3,563 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2023 |  | $ | 133,000,000 |  |  |  | 211 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2022 |  | $ | 339,400,000 |  |  |  | 3,630 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2022 |  | $ | 133,000,000 |  |  |  | 232 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2021 |  | $ | 399,400,000 |  |  |  | 4,116 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2021 |  | $ | 133,000,000 |  |  |  | 309 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2020 |  | $ | 288,400,000 |  |  |  | 4,431 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2020 |  | $ | 100,000,000 |  |  |  | 319 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2019 |  | $ | 277,400,000 |  |  |  | 4,080 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2019 |  | $ | 100,000,000 |  |  |  | 283 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2018 |  | $ | 288,000,000 |  |  |  | 3,921 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2018 |  | $ | 100,000,000 |  |  |  | 282 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2017 |  | $ | 275,000,000 |  |  |  | 4,265 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2017 |  | $ | 100,000,000 |  |  |  | 293 | (b) |  |  | 25 |  |  |  | 25 | (d) |  | MRPS
October 31, 2016 |  | $ | 306,000,000 |  |  |  | 3,454 | (a) |  |  | - |  |  |  | - |  |  | Loan
October 31, 2015 |  | $ | 353,000,000 |  |  |  | 3,316 | (a) |  |  | - |  |  |  | - |  |  | Loan
(a) Calculated by subtracting the Fund's total liabilities (not including notes payable and MRPS) from the Fund's total assets and dividing this by the amount of notes payable outstanding, and by multiplying the result by 1,000. (b) Calculated by subtracting the Fund's total liabilities (not including MRPS) from the Fund's total assets and dividing this by the number of MRPS outstanding, and by multiplying the result by 25. (c) "Liquidating Preference per Preferred Share" means the amount to which a holder of preferred shares would be entitled upon the liquidation of the Fund in preference to common shareholders, expressed as a dollar amount per preferred share. (d) The MRPS are not listed on any exchange or automated quotation system. The MRPS are considered debt of the issuer; and the liquidation preference approximates fair value. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Securities Highlights Audited, Note [Text Block] |  | The following table sets forth information regarding the Fund's outstanding bank loans and MRP Shares as of the end of each of the Fund's last ten fiscal years, as applicable. The information in the table shown below comes from the Fund's financial statements for the fiscal year ended October 31, 2024, and each of the prior nine years then ended, all of which have been audited by Deloitte & Touche LLP, the Fund's independent registered public accounting firm. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Investment Objectives and Practices [Text Block] |  | INVESTMENT OBJECTIVE AND PRINCIPAL INVESTMENT STRATEGIES Investment Objective The Fund's investment objective is to provide total return through a combination of capital appreciation and current income. The Fund's investment objective may be changed by the Board of Trustees without a shareholder vote, although the Fund will give shareholders at least 60 days' written notice of any change to the Fund's investment objective. The Fund makes no assurance that it will realize its objective. An investment in the Fund may be speculative in that it involves a high degree of risk and should not constitute a complete investment program. See "Risk Factors." Principal Investment Strategies Under normal circumstances, the Fund invests at least 80% of its managed assets in a diversified portfolio of convertible securities and non-convertible income securities. This is a non-fundamental policy and may be changed by the Board of Trustees of the Fund provided that shareholders are provided with at least 60 days' prior written notice of any change as required by the rules under the 1940 Act. The portion of the Fund's assets invested in convertible securities and non-convertible income securities will vary from time to time consistent with the Fund's investment objective, changes in equity prices and changes in interest rates and other economic and market factors, although, under normal circumstances, the Fund will invest at least 35% of its managed assets in convertible securities. The Fund invests in securities with a broad range of maturities. Convertible Securities. The Fund is not limited in the percentage of its assets invested in convertible securities, and investment in convertible securities forms an important part of the Fund's principal investment strategies. Under normal circumstances, the Fund will invest at least 35% of its managed assets in convertible securities. A convertible security is a debt security, debenture, note or preferred stock that may be converted into an equity security (typically common stock of the same issuer) at a predetermined price (the "conversion price"). Depending upon the relationship of the conversion price to the market value of the underlying security, a convertible security may trade more like an equity security than a debt instrument. The Fund may invest in convertible securities of any rating. Calamos typically applies a four-step approach when buying and selling convertible securities for the Fund, which includes: 1. Evaluating the default risk of the convertible security using traditional credit analysis; 2. Analyzing the convertible's underlying common stock to determine its capital appreciation potential; 3. Assessing the risk/return potential of the convertible security; and 4. Evaluating the convertible security's impact on the overall composition of the Fund and its diversification strategy. In analyzing the appreciation potential of the underlying common stock and the default risk of the convertible security, Calamos generally considers the issuer's: ● financial soundness; ● ability to make interest and dividend payments; ● earnings and cash-flow forecast; and ● quality of management. Synthetic Convertible Instruments. The Fund may invest in "synthetic" convertible instruments. A synthetic convertible instrument is a financial instrument (or two or more securities held in tandem) that is designed to simulate the economic characteristics of another instrument (i.e., a convertible security) through the combined economic features of a collection of other securities or assets. Calamos may create a synthetic convertible instrument by combining separate securities that possess the two principal characteristics of a true convertible security, i.e., a fixed-income security ("fixed-income component", which may be a convertible or non-convertible security) and the right to acquire an equity security ("convertible component"). The fixed-income component is achieved by investing in fixed-income securities such as bonds, preferred stocks and money market instruments. The convertible component is achieved by investing in warrants or options to buy common stock at a certain exercise price, or options on a stock index. The Fund may also invest in synthetic convertible instruments created by third parties, typically investment banks. Synthetic convertible instruments created by such parties may be designed to simulate the characteristics of traditional convertible securities or may be designed to alter or emphasize a particular feature. Traditional convertible securities typically offer the opportunity for stable cash flows with the ability to participate in capital appreciation of the underlying common stock. Traditional convertible securities are exercisable at the option of the holder. Synthetic convertible instruments may alter these characteristics by offering enhanced yields in exchange for reduced capital appreciation, additional risk of loss, or any combination of these features. Synthetic convertible instruments may include structured notes, equity-linked notes, mandatory convertibles and combinations of securities and instruments, such as a debt instrument combined with a forward contract. The Fund's holdings of synthetic convertible instruments are considered convertible securities for purposes of the Fund's policy to invest at least 35% of its managed assets in convertible securities and 80% of its managed assets in a diversified portfolio of convertible securities and non-convertible income securities. Some examples of these securities include the following: Preferred equity redeemable cumulative stock ("PERCS") are shares that automatically convert into one ordinary share upon maturity. They are usually issued at the prevailing share price, convertible into one ordinary share, with an enhanced dividend yield. PERCS pay a higher dividend than common shares, but the equity appreciation is capped. Above a certain share price, the conversion ratio will fall as the stock rises, capping the appreciation at that level. Below this level, the conversion ratio remains one-for-one, giving the same downside exposure as the ordinary shares, excluding the income difference. Dividend enhanced convertible stock ("DECS") are either preference shares or subordinated bonds. These, like PERCS, mandatorily convert into ordinary shares at maturity, if not already converted. DECS give no significant loss protection and involve a risk of loss comparable to investing directly in equity securities, with lower relative direct bond characteristics and interest rate exposure. As with PERCS, some of the appreciation potential is capped and in return, the investor receives an enhanced potential yield. Unlike PERCS, however, the investor's appreciation potential is not capped. Instead, the investor limits its ability to participate in appreciation within a range of prices. Preferred Redeemable Increased Dividend Equity Security ("PRIDES") are synthetic securities consisting of a forward contract to purchase the issuer's underlying security and an interest bearing deposit. Interest payments are made at regular intervals, and conversion into the underlying security is mandatory at maturity. Similar to convertible securities, PRIDES allow investors the potential to earn stable cash flows while still participating in the appreciation of an underlying stock. The Fund may also purchase convertible structured notes. Convertible structured notes are fixed income debentures linked to equity. Convertible structured notes have the attributes of a convertible security; however, the investment bank that issued the convertible note assumes the credit risk associated with the investment, rather than the issuer of the underlying common stock into which the note is convertible. Different companies may issue the fixed-income and convertible components, which may be purchased separately and at different times. The Fund remains subject to the credit risk of the issuing investment bank. Certain convertible debt securities include a "put option" which entitles the Fund to sell the security to the issuer before maturity at a stated price, which may represent a premium over the stated principal amount of the debt security. Conversely many convertible securities are issued with a "call" feature that allows the security's issuers to choose when to redeem the security. Non-Convertible Income Securities. The Fund will also invest in non-convertible income securities. The Fund's investments in non-convertible income securities may have fixed or variable principal payments and all types of interest rate and dividend payment and reset terms, including fixed rate, adjustable rate, zero coupon, contingent, deferred, payment in kind and auction rate features. High Yield Securities. A substantial portion of the Fund's assets may be invested in below investment grade (high yield, high risk) securities for either current income or capital appreciation or both. These securities are rated Ba or lower by Moody's or BB or lower by Standard & Poor's or are unrated securities of comparable quality as determined by Calamos, the Fund's investment adviser. The Fund may invest in high yield securities of any rating. The Fund may, but currently does not intend to, invest up to 5% of its managed assets in distressed securities that are in default or the issuers of which are in bankruptcy. Non-convertible debt securities rated below investment grade are commonly referred to as "junk bonds" and are considered speculative with respect to the issuer's capacity to pay interest and repay principal. Below investment grade securities involve greater risk of loss, are subject to greater price volatility and are less liquid, especially during periods of economic uncertainty or change, than higher rated securities. Foreign Securities. Although the Fund primarily invests in securities of U.S. issuers, the Fund may invest up to 25% of its net assets in securities of foreign issuers in developed and emerging markets, including debt and equity securities of corporate issuers and debt securities of government issuers. A foreign issuer is a foreign government or a company organized under the laws of a foreign country. In analyzing the foreign issuers in which the Fund may invest, Calamos will generally consider a number of factors that may characterize the issuer's economic ties to a particular foreign country or region. Such factors may include any or all of the following: the characteristics of the economy in the principal country or countries in which the issuer sells it goods and/or services; the stability of the currency in the issuer's country of organization; the laws with respect to international trade and property rights in the issuer's country of organization; and the tax, accounting and regulatory requirements of the issuer's country of organization. Options Writing. The Fund may seek to generate income from option premiums by writing (selling) options. The Fund may write (sell) call options (i) on a portion of the equity securities (including equity securities obtainable by the Fund through the exercise of its rights with respect to convertible securities it owns) in the Fund's portfolio and (ii) on broad-based securities indices (such as the S&P 500 or MSCI EAFE) or certain ETFs (exchange traded funds) that trade like common stocks but seek to replicate such market indices. In addition, to seek to offset some of the risk of a potential decline in value of certain long positions, the Fund may also purchase put options on individual securities, broad-based securities indices (such as the S&P 500 or MSCI EAFE), or certain ETFs that trade like common stocks but seek to replicate market indices. See " — Options in General" below. Options in General. The Fund may purchase and sell options on stocks, indices, rates, credit spreads or currencies. A call option, upon payment of a premium, gives the purchaser of the option the right to buy, and the seller the obligation to sell, the underlying security, index or other instrument at the exercise price. A put option gives the purchaser of the option, upon payment of a premium, the right to sell, and the seller the obligation to buy, the underlying security, index, or other instrument at the exercise price. Certain options, known as "American style" options, may be exercised at any time during the term of the option. Other options, known as "European style" options, may be exercised only on the expiration date of the option. The Fund expects that substantially all of the options written by the Fund will be American style options. The Fund is authorized to purchase and sell exchange listed options and over-the-counter options ("OTC options"). Exchange listed options are issued by a regulated intermediary such as the Options Clearing Corporation ("OCC"), which guarantees the performance of the obligations of the parties to such options. In addition, the Fund may purchase instruments structured by broker-dealers or investment banks that package or possess economic characteristics of options. The discussion below uses the OCC as an example, but is also applicable to other financial intermediaries. With certain exceptions, OCC issued and exchange listed options generally settle by physical delivery of the underlying security or currency, although in the future cash settlement may become available. Index options are cash settled for the net amount, if any, by which the option is "in-the-money" (i.e., where the value of the underlying instrument exceeds, in the case of a call option, or is less than, in the case of a put option, the exercise price of the option) at the time the option is exercised. Frequently, rather than taking or making delivery of the underlying instrument through the process of exercising the option, listed options are closed by entering into offsetting purchase or sale transactions that do not result in ownership of the new option. OTC options are purchased from or sold to securities dealers, financial institutions or other parties ("Counterparties") through direct bilateral agreement with the Counterparty. In contrast to exchange listed options, which generally have standardized terms and performance mechanics, all the terms of an OTC option, including such terms as method of settlement, term, exercise price, premium, guarantees and security, are set by negotiation of the parties. The Fund may sell OTC options (other than OTC currency options) that are subject to a buy-back provision permitting the Fund to require the Counterparty to sell the option back to the Fund at a formula price within seven days. The Fund expects generally to enter into OTC options that have cash settlement provisions, although it is not required to do so. The staff of the Commission currently takes the position that OTC options purchased by a fund, and portfolio securities "covering" the amount of a fund's obligation pursuant to an OTC option sold by it (or the amount of assets equal to the formula price for the repurchase of the option, if any, less the amount by which the option is in-the-money) are illiquid. OTC options purchased by the Fund and any portfolio securities used to cover obligations pursuant to such options are not considered illiquid by Calamos for the purposes of the Fund's limitation on investments in illiquid securities. The Fund will write call options and put options only if they are "covered." For example, a call option written by the Fund will require the Fund to hold the securities subject to the call (or securities convertible into those securities without additional consideration) or to segregate cash or liquid assets sufficient to purchase and deliver the securities if the call is exercised. The principal factors affecting the market value of a put or a call option include supply and demand, interest rates, the current market price of the underlying security or index in relation to the exercise price of the option, the volatility of the underlying security or index, and the time remaining until the expiration date. Rule 144A Securities. The Fund may invest without limit in certain securities, such as convertible and debt securities, that are typically purchased in transactions exempt from the registration requirements of the 1933 Act pursuant to Rule 144A under that Act. Rule 144A Securities may only be sold to qualified institutional buyers, such as the Fund. Any resale of these securities must generally be effected through a sale that is registered under the 1933 Act or otherwise exempted or excepted from such registration requirements. Under the supervision and oversight of the Fund's Board of Trustees, Calamos will determine whether Rule 144A Securities are liquid. Typically, the Fund purchases Rule 144A Securities only if Calamos has determined them to be liquid. If any Rule 144A Security held by the Fund should become illiquid, the value of the security may be reduced and a sale of the security may be more difficult. Loans. The Fund may invest in loan participations and other direct claims against a borrower. The corporate loans in which the Fund may invest primarily consist of direct obligations of a borrower and may include debtor in possession financings pursuant to Chapter 11 of the U.S. Bankruptcy Code, obligations of a borrower issued in connection with a restructuring pursuant to Chapter 11 of the U.S. Bankruptcy Code, leveraged buy-out loans, leveraged recapitalization loans, receivables purchase facilities, and privately placed notes. The Fund may invest in a corporate loan at origination as a co-lender or by acquiring in the secondary market participations in, assignments of or novations of a corporate loan. By purchasing a participation, the Fund acquires some or all of the interest of a bank or other lending institution in a loan to a corporate or government borrower. The participations typically will result in the Fund having a contractual relationship only with the lender not the borrower. The Fund will have the right to receive payments of principal, interest and any fees to which it is entitled only from the lender selling the participation and only upon receipt by the lender of the payments from the borrower. Many such loans are secured, although some may be unsecured. Such loans may be in default at the time of purchase. Loans that are fully secured offer the Fund more protection than an unsecured loan in the event of non-payment of scheduled interest or principal. However, there is no assurance that the liquidation of collateral from a secured loan would satisfy the corporate borrower's obligation, or that the collateral can be liquidated. Direct debt instruments may involve a risk of loss in case of default or insolvency of the borrower and may offer less legal protection to the Fund in the event of fraud or misrepresentation. In addition, loan participations involve a risk of insolvency of the lending bank or other financial intermediary. The markets in such loans are not regulated by federal securities laws or the Commission. Preferred Shares. The Fund may invest in preferred stock. The preferred stock in which the Fund typically will invest will be convertible securities. Preferred shares are equity securities, but they have many characteristics of fixed income securities, such as a fixed dividend payment rate and/or a liquidity preference over the issuer's common shares. However, because preferred stocks are equity securities, they may be more susceptible to risks traditionally associated with equity investments than the Fund's fixed income securities. REITs. The Fund may invest in securities of REITs, including debt securities they may issue. REITs primarily invest in income-producing real estate or real estate related loans or interests. REITs are generally classified as equity REITs, mortgage REITs or a combination of equity and mortgage REITs. Equity REITs invest the majority of their assets directly in real property and derive income primarily from the collection of rents. Equity REITs can also realize capital gains by selling properties that have appreciated in value. Mortgage REITs invest the majority of their assets in real estate mortgages and derive income from the collection of interest payments. REITs are not taxed on income distributed to shareholders provided they comply with the applicable requirements of the Code. The Fund will indirectly bear its proportionate share of any management and other expenses paid by REITs in which it invests in addition to the expenses paid by the Fund. Debt securities issued by REITs are, for the most part, general and unsecured obligations and are subject to risks associated with REITs. U.S. Government Securities. U.S. government securities in which the Fund invests include debt obligations of varying maturities issued by the U.S. Treasury or issued or guaranteed by an agency or instrumentality of the U.S. government, including the Federal Housing Administration, Federal Financing Bank, Farmers Home Administration, Export-Import Bank of the United States, Small Business Administration, Government National Mortgage Association ("GNMA"), General Services Administration, Central Bank for Cooperatives, Federal Farm Credit Banks, Federal Home Loan Banks, Federal Home Loan Mortgage Corporation ("FHLMC"), Federal National Mortgage Association ("FNMA"), Maritime Administration, Tennessee Valley Authority, District of Columbia Armory Board, Student Loan Marketing Association, Resolution Fund Corporation and various institutions that previously were or currently are part of the Farm Credit System (which has been undergoing reorganization since 1987). Some U.S. government securities, such as U.S. Treasury bills, Treasury notes and Treasury bonds, which differ only in their interest rates, maturities and times of issuance, are supported by the full faith and credit of the United States. Others are supported only by: (i) the right of the issuer to borrow from the U.S. Treasury, such as securities of the Federal Home Loan Banks; (ii) the discretionary authority of the U.S. government to purchase the agency's obligations, such as securities of the FNMA; or (iii) only the credit of the issuer. No assurance can be given that the U.S. government will provide financial support in the future to U.S. government agencies, authorities or instrumentalities that are not supported by the full faith and credit of the United States. Securities guaranteed as to principal and interest by the U.S. government, its agencies, authorities or instrumentalities include: (i) securities for which the payment of principal and interest is backed by an irrevocable letter of credit issued by the U.S. government or any of its agencies, authorities or instrumentalities; and (ii) participations in loans made to non-U.S. governments or other entities that are so guaranteed. The secondary market for certain of these participations is limited and, therefore, may be regarded as illiquid. Zero Coupon Securities. The securities in which the Fund invests may include zero coupon securities, which are debt obligations that are issued or purchased at a significant discount from face value. The discount may approximate the total amount of interest the security will accrue and compound over the period until maturity or the particular interest payment date at a rate of interest reflecting the market rate of the security at the time of issuance. Zero coupon securities do not require the periodic payment of interest. These investments benefit the issuer by mitigating its need for cash to meet debt service, but generally require a higher rate of return to attract investors who are willing to defer receipt of cash. These investments involve greater interest rate risk and may experience greater volatility in market value than U.S. government securities that make regular payments of interest. The Fund accrues income on these investments for tax and accounting purposes, which is distributable to shareholders and which, because no cash is received at the time of accrual, may require the liquidation of other portfolio securities to satisfy the Fund's distribution obligations or to reduce or eliminate tax at the Fund level, in which case the Fund will forgo the purchase of additional income producing assets with these funds. Zero coupon U.S. government securities include STRIPS and CUBES, which are issued by the U.S. Treasury as component parts of U.S. Treasury bonds and represent scheduled interest and principal payments on the bonds. Equity Securities. Consistent with its objective, the Fund may invest in equity securities, including common and preferred stocks, warrants, rights and depository receipts. Equity securities, such as common stock, generally represent an ownership interest in a company. Therefore, the Fund participates in the financial success or failure of any company in which it has an equity interest. Although equity securities have historically generated higher average returns than fixed income securities, equity securities have also experienced significantly more volatility in those returns. An adverse event, such as an unfavorable earnings report, may depress the value of a particular equity security held by the Fund. Also, the price of equity securities, particularly common stocks, are sensitive to general changes in economic conditions and movements in the stock market. A drop in the stock market may depress the price of equity securities held by the Fund. See also " — Preferred Shares" below. Other Investment Companies. The Fund may invest in the securities of other investment companies to the extent that such investments are consistent with the Fund's investment objective and policies and are permissible under the 1940 Act. Under the 1940 Act, the Fund may not acquire the securities of other domestic or non-U.S. investment companies if, as a result, (1) more than 10% of the Fund's total assets would be invested in securities of other investment companies, (2) such purchase would result in more than 3% of the total outstanding voting securities of any one investment company being held by the Fund, (3) more than 5% of the Fund's total assets would be invested in any one investment company, or (4) such purchase would result in more than 10% of the total outstanding voting securities of a registered closed-end investment company being held by the Fund. These limitations do not apply to, among other things, the purchase of shares of money market funds, of certain related funds or of funds with exemptive relief, or of any investment company in connection with a merger, consolidation, reorganization or acquisition of substantially all the assets of another investment company, or to purchases of investment companies made in accordance with SEC exemptive relief or rule. The Fund, as a holder of the securities of other investment companies, will bear its pro rata portion of the other investment companies' expenses, including advisory fees. These expenses are in addition to the direct expenses of the Fund's own operations. In addition, the Fund's performance may be magnified positively or negatively by virtue of its investment in other investment companies. Temporary and Defensive Investments. Under unusual market or economic conditions or for temporary defensive purposes, the Fund may invest in a manner that is inconsistent with its principal investment strategies described herein. In those situations, the Fund may invest up to 100% of its managed assets in securities issued or guaranteed by the U.S. government or its instrumentalities or agencies, certificates of deposit, bankers' acceptances and other bank obligations, commercial paper rated in the highest category by a nationally recognized statistical rating organization ("NRSRO") or other fixed income securities deemed by Calamos to be consistent with a defensive posture, or may hold cash. The yield on such securities may be lower than the yield on lower rated fixed income securities. During such periods, the Fund may not be able to achieve its investment objective. Repurchase Agreements. The Fund may enter into repurchase agreements with broker-dealers, member banks of the Federal Reserve System and other financial institutions. Repurchase agreements are arrangements under which the Fund purchases securities and the seller agrees to repurchase the securities within a specific time and at a specific price. The repurchase price is generally higher than the Fund's purchase price, with the difference being income to the Fund. The counterparty's obligations under the repurchase agreement are typically collateralized with U.S. Treasury and/or agency obligations with a market value of not less than 100% of the obligations, valued daily. Collateral is typically held by the Fund's custodian in a segregated, safekeeping account for the benefit of the Fund. Repurchase agreements afford the Fund an opportunity to earn income on temporarily available cash. In the event of commencement of bankruptcy or insolvency proceedings with respect to the issuer of the repurchase agreement before repurchase of the security under a repurchase agreement, the Fund may encounter losses and delay and incur costs before being able to sell the security. Such a delay may involve loss of interest or a decline in price of the security. If the court characterizes the transaction as a loan and the Fund has not perfected a security interest in the security, the Fund may be required to return the security to the seller's estate and be treated as an unsecured creditor of the seller. As an unsecured creditor, the Fund would be at risk of losing some or all of the principal and interest involved in the transaction. Lending of Portfolio Securities. The Fund has authorized SSB as securities lending agent to lend securities to registered broker-dealers or other institutional investors under agreements which require that the loans be secured continuously by collateral received in cash under the SSB Agreement. Counterparties to securities lending transactions through SSB are generally SSB’s approved counterparty list, subject to a concentration limit imposed by the Fund which precludes any single counterparty from constituting 25% or more of the Fund’s securities lending transactions then outstanding. The Fund has the right to limit or to prohibit altogether securities lending with otherwise eligible counterparties, subject to the potential for an increase in the Fund’s borrowing cost of either .25% or .45% per annum if such limits or prohibitions disqualify multiple counterparties which account for more than 25% or 50%, respectively, of the Fund’s recent securities lending transactions. Cash collateral received by SSB on behalf of the Fund is deposited into a custodial account in the name of the Fund before being treated as refinancing a portion of the amounts borrowed under the SSB Agreement. The interest paid by the Fund under the SSB Agreement is not impacted by whether the funding is through an advance by SSB or by receipt of collateral for securities lending. Under the terms of the SSB Agreement, the Fund is required to return the value of the collateral to the borrower at the termination of the selected securities loan(s). The Fund does not use affiliated agents in managing its lending program. The Fund continues to be entitled to receive the equivalent of the interest or dividends paid by the issuer on the securities loaned as well as the benefit of an increase and the detriment of any decrease in the market value of the securities loaned and would also receive compensation based on investment of the collateral, but bears the risk of loss on any collateral so invested. The Fund would not, however, have the right to vote any securities having voting rights during the existence of the loan, but could seek to call the loan in anticipation of an important vote to be taken among holders of the securities or of the giving or withholding of consent on a material matter affecting the investment. As with other extensions of credit, there are risks of delay in recovery or even loss of rights in the collateral should the borrower of the securities fail financially. The Fund remains liable for the return of the pledged collateral or cash of an equivalent value. At no time would the value of the securities loaned exceed 33 1/3% of the value of the Fund's managed assets. The securities lending arrangement with SSB involves characteristics common in arm’s length relationships in which one party may benefit at the expense of the other party. See "Description of Securities" for more information on lending of portfolio securities. Portfolio Turnover. Although the Fund does not purchase securities with a view to rapid turnover, there are no limitations on the length of time that portfolio securities must be held. Portfolio turnover can occur for a number of reasons, including calls for redemption, general conditions in the securities markets, more favorable investment opportunities in other securities, or other factors relating to the desirability of holding or changing a portfolio investment. The portfolio turnover rates may vary greatly from year to year. A high rate of portfolio turnover in the Fund would result in increased transaction expense, which must be borne by the Fund. High portfolio turnover may also result in the realization of capital gains or losses and, to the extent net short-term capital gains are realized, any distributions resulting from such gains will be considered ordinary income for federal income tax purposes. Fundamental Investment Restrictions. As more fully described in the Fund's statement of additional information, under the Fund's fundamental investment restrictions, the Fund may not: (1) issue senior securities, except as permitted by the 1940 Act and the rules and interpretive positions of the Commission thereunder; (2) borrow money, except as permitted by the 1940 Act and the rules and interpretive positions of the Commission thereunder; (3) invest in real estate, except that the Fund may invest in securities of issuers that invest in real estate or interests therein, securities that are secured by real estate or interests therein, securities of real estate investment funds and mortgage-backed securities; (4) make loans, except by the purchase of debt obligations, by entering into repurchase agreements or through the lending of portfolio securities and as otherwise permitted by the 1940 Act and the rules and interpretive positions of the Commission thereunder; (5) invest in physical commodities or contracts relating to physical commodities; (6) act as an underwriter, except as it may be deemed to be an underwriter in a sale of securities held in its portfolio; (7) make any investment inconsistent with the Fund's classification as a diversified investment company under the 1940 Act and the rules and interpretive positions of the Commission thereunder; and (8) concentrate its investments in securities of companies in any particular industry as defined in the 1940 Act and the rules and interpretive positions of the Commission thereunder. This description of the Fund's fundamental investment restrictions is a summary only and to the extent it differs from the discussion of fundamental investment restrictions contained in the Fund's statement of additional information, the description in the statement of additional information controls. These restrictions may not be changed without the approval of the holders of a majority of the Fund's outstanding voting securities. All other investment policies of the Fund are considered non-fundamental and may be changed by the Board of Trustees without prior approval of the Fund's outstanding voting shares, although the Fund will give shareholders at least 60 days' notice of any changes to the Fund's investment objective. See "Investment Restrictions" on page S-24 of the Fund's statement of additional information. Conflicts of Interest Conflicts of interest may arise from the fact that Calamos and its affiliates carry on substantial investment activities for other clients, in which the Fund does not have an interest, some of which may have investment strategies similar to those of the Fund. Calamos or its affiliates may have financial incentives to favor certain of these accounts over the Fund. Any of their proprietary accounts or other customer accounts may compete with the Fund for specific trades. Calamos or its affiliates may give advice and recommend securities to, or buy or sell securities for, other accounts and customers, which advice or securities recommended may differ from advice given to, or securities recommended or bought or sold for, the Fund, even though their investment objectives may be the same as, or similar to, the Fund's investment objective. When two or more clients advised by Calamos or its affiliates seek to purchase or sell the same publicly traded securities, the securities actually purchased or sold will be allocated among the clients on a good faith equitable basis by Calamos in its discretion and in accordance with the clients' various investment objectives and Calamos' procedures. In some cases, this system may adversely affect the price or size of the position the Fund may obtain or sell. In other cases, the Fund's ability to participate in volume transactions may produce better execution for the Fund. Calamos will evaluate a variety of factors in determining whether a particular investment opportunity or strategy is appropriate and feasible for a particular entity or account at a particular time, including, but not limited to, the following: (1) the nature of the investment opportunity taken in the context of the other investments available at the time; (2) the liquidity of the investment relative to the needs of the particular entity or account; (3) the availability of the opportunity (i.e., size of obtainable position); (4) the transaction costs involved; and (5) the investment or regulatory limitations applicable to the particular entity or account. Because these considerations may differ when applied to the Fund and relevant accounts under management in the context of any particular investment opportunity, the Fund's investment activities, on the one hand, and other managed accounts, on the other hand, may differ considerably from time to time. In addition, the Fund's fees and expenses will differ from those of the other managed accounts. Accordingly, investors should be aware that the Fund's future performance and future performance of other accounts of Calamos may vary. Situations may occur when the Fund could be disadvantaged because of the investment activities conducted by Calamos and its affiliates for their other accounts. Such situations may be based on, among other things, the following: (1) legal or internal restrictions on the combined size of positions that may be taken for the Fund or the other accounts, thereby limiting the size of the Fund's position; (2) the difficulty of liquidating an investment for the Fund or the other accounts where the market cannot absorb the sale of the combined position; or (3) limits on co-investing in negotiated transactions under the 1940 Act. Calamos and its principals, officers, employees, and affiliates may buy and sell securities or other investments for their own accounts and may have actual or potential conflicts of interest with respect to investments made on the Fund's behalf. As a result of differing trading and investment strategies or constraints, positions may be taken by principals, officers, employees, and affiliates of Calamos that are the same as, different from, or made at a different time than positions taken for the Fund. Calamos' investment management fee is a percentage of the Fund's managed assets, and Calamos' investment management fee will be higher if the Fund sells additional common shares or employs leverage. Accordingly, Calamos will benefit from the sale of additional common shares, preferred shares, or debt securities and may have an incentive to be more aggressive with respect to the use of leverage by the Fund. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk Factors [Table Text Block] |  | RISK FACTORS Investing in any of our securities involves risk, including the risk that you may receive little or no return on your investment or even that you may lose part or all of your investment. Therefore, before investing in any of our securities you should consider carefully the following risks, as well as any risk factors included in the applicable prospectus supplement. Fund Risks The principal risks are presented in alphabetical order to facilitate finding particular risks and comparing them with other funds. Each risk summarized below, including Management Risk, Portfolio Selection Risk, Equity Securities Risk, Emerging Market Risk and Foreign Securities Risk, among others, is considered a "principal risk" of investing in the Fund, regardless of the order in which it appears. General. The Fund is a diversified, closed-end management investment company designed primarily as a long-term investment and not as a trading tool. The Fund invests primarily in a diversified portfolio of convertible securities and non-convertible income securities. An investment in the Fund's common shares may be speculative and it involves a high degree of risk. The Fund is not a complete investment program. Due to the uncertainty in all investments, there can be no assurance that the Fund will achieve its investment objective. American Depositary Receipts Risk. The stocks of most foreign companies that trade in the U.S. markets are traded as ADRs. U.S. depositary banks issue these stocks. Each ADR represents one or more shares of foreign stock or a fraction of a share. The price of an ADR corresponds to the price of the foreign stock in its home market, adjusted to the ratio of the ADRs to foreign company shares. Therefore, while purchasing a security on a U.S. exchange, the risks inherently associated with foreign investing still apply to ADRs. Antitakeover Provisions. The Fund's Agreement and Declaration of Trust and By-Laws include provisions that could limit the ability of other entities or persons to acquire control of the Fund or to change the composition of its Board of Trustees. Such provisions could limit the ability of shareholders to sell their shares at a premium over prevailing market prices by discouraging a third party from seeking to obtain control of the Fund. These provisions include staggered terms of office for the Trustees, advance notice requirements for shareholder proposals, and super-majority voting requirements for certain transactions with affiliates, converting the Fund to an open-end investment company or a merger, asset sale or similar transaction. Holders of preferred shares have voting rights in addition to and separate from the voting rights of common shareholders with respect to certain of these matters. Holders of any preferred shares, voting separately as a single class, have the right to elect at least two Trustees at all times. See "Description of Securities — Preferred Shares" and "Certain Provisions of the Agreement and Declaration of Trust and By-Laws, Including Antitakeover Provisions." The holders of preferred shares or debt, if any, on the one hand, and the holders of the common shares, on the other, may have interests that conflict with each other in certain situations, including conflicts that relate to the fees and expenses of the Fund. For more information on potential conflicts of interest between holders of common shares and holders of preferred shares, see "Leverage Risk" above. Cash Holdings Risk. To the extent the Fund holds cash positions, the Fund risks achieving lower returns and potential lost opportunities to participate in market appreciation which could negatively impact the Fund's performance and ability to achieve its investment objective. Contingent Liabilities Risk. Entering into derivative contracts in order to pursue the Fund's various hedging strategies could require the Fund to fund cash payments in the future under certain circumstances, including an event of default or other early termination event, or the decision by a counterparty to request margin in the form of securities or other forms of collateral under the terms of the derivative contract or applicable laws. The amounts due with respect to a derivative contract would generally be equal to the unrealized loss of the open positions with the respective counterparty and could also include other fees and charges. These payments are contingent liabilities and therefore may not appear on the Fund's balance sheet. The Fund's ability to fund these contingent liabilities will depend on the liquidity of the Fund's assets and access to capital at the time, and the need to fund these contingent liabilities could adversely impact our financial condition. Convertible Securities Risk. The value of a convertible security is influenced by both the yield of non-convertible securities of comparable issuers and by the value of the underlying common stock. The value of a convertible security viewed without regard to its conversion feature (i.e., strictly on the basis of its yield) is sometimes referred to as its "investment value." A convertible security's investment value tends to decline as prevailing interest rate levels increase. Conversely, a convertible security's investment value tends to increase as prevailing interest rate levels decline. However, a convertible security's market value tends to reflect the market price of the common stock of the issuing company when that stock price is greater than the convertible security's "conversion price." The conversion price is defined as the predetermined price at which the convertible security could be exchanged for the associated stock. As the market price of the underlying common stock declines, the price of the convertible security tends to be influenced more by the yield of the convertible security and changes in interest rates. Thus, the convertible security may not decline in price to the same extent as the underlying common stock. In the event of a liquidation of the issuing company, holders of convertible securities would be paid before the company's common stockholders. Correlation Risk. Imperfect correlation between the value of derivative instruments and the underlying assets of the Fund creates the possibility that the loss on such instruments may be greater than the gain in the value of the underlying assets in the Fund's portfolio. Counterparty and Settlement Risk. Trading options, futures contracts, swaps and other derivative financial instruments entails credit risk with respect to the counterparties with whom and through which the Fund trades. Such instruments when traded over the counter do not include the same protections as may apply to trading derivatives on organized exchanges. Substantial losses may arise from the insolvency, bankruptcy or default of a counterparty and risk of settlement default of parties with whom the Fund trades securities. This risk may be heightened during volatile market conditions. Settlement mechanisms in emerging markets are generally less developed and reliable than those in more developed countries thus increasing the risks. In the past, broker-dealers and other financial institutions have experienced extreme financial difficulty, sometimes resulting in bankruptcy of the institution. Although Calamos monitors the creditworthiness of the Fund's counterparties, there can be no assurance that the Fund's counterparties will not experience similar difficulties, possibly resulting in losses to the Fund. If a counterparty becomes bankrupt or otherwise fails to perform its obligations under a derivative contract due to financial difficulties, such bankruptcy or failure to perform is likely to result in a default under such derivative contract, unless such default is cured. Default by a party with whom the Fund enters into a hedging transaction may result in the loss of unrealized profits, leaving the Fund with unsecured exposure and force the Fund to cover its resale commitments, if any, at the then current market price. It may not always be possible to dispose of or close out a hedging position without the consent of the hedging counterparty, and the Fund may not be able to enter into an offsetting contract in order to cover its risk. The Fund cannot assure its shareholders that a liquid secondary market will exist for hedging instruments purchased or sold, and the Fund may be required to maintain a position until exercise or expiration, which could result in losses. Furthermore, upon the bankruptcy of a counterparty, the Fund may experience significant delays in obtaining any recovery under the derivative contract in a dissolution, assignment for the benefit of creditors, liquidation, winding-up, bankruptcy, or other analogous proceeding. In addition, in the event of the insolvency of a counterparty to a derivative transaction, the derivative transaction would typically be terminated at its fair market value. If the Fund is owed this fair market value in the termination of the derivative transaction and its claim is unsecured, the Fund will be treated as a general creditor of such counterparty, and will not have any claim with respect to the underlying security. The Fund may obtain only a limited recovery or may obtain no recovery in such circumstances and the enforceability of agreements for hedging transactions may depend on compliance with applicable statutory and other regulatory requirements and, depending on the identity of the counterparty, applicable international requirements. Certain interest rate and credit default swaps are subject to mandatory clearing, in which case a central clearing counterparty stands between each buyer and seller and effectively guarantees performance of each derivative contract, to the extent of its available resources for such purpose. As a result, the counterparty risk is now shifted from bilateral risk between the parties to the individual credit risk of the central clearing counterparty and the futures commission merchant through which the Fund holds its cleared position. Even in such case, there can be no assurance that a clearing house, or its members, will satisfy the clearing house's obligations to the Fund. Uncleared derivatives have no such protection; each party bears the risk that its direct counterparty will default. "Covenant-Lite" Loans Risk. Some of the loans in which the Fund may invest may be "covenant-lite" loans, which means the loans contain fewer or no maintenance covenants than other loans and do not include terms which allow the lender to monitor the performance of the borrower and declare a default if certain criteria are breached. The Fund may experience delays in enforcing its rights on its holdings of covenant-lite loans. Credit Risk. An issuer of a fixed income security could be downgraded or default. If the Fund holds securities that have been downgraded, or that default on payment, the Fund's performance could be negatively affected. Currency Risk. To the extent that the Fund invests in securities or other instruments denominated in or indexed to foreign currencies, changes in currency exchange rates bring an added dimension of risk. Currency fluctuations could negatively impact investment gains or add to investment losses. Although the Fund may attempt to hedge against currency risk, the hedging instruments may not always perform as the Fund expects and could produce losses. Suitable hedging instruments may not be available for currencies of emerging market countries. The Fund's investment adviser may determine not to hedge currency risks, even if suitable instruments appear to be available. Cybersecurity Risk. Investment companies, such as the Fund, and their service providers are exposed to operational and information security risks resulting from cyberattacks, which may result in financial losses to a fund and its shareholders. Cyber-attacks include, among other behaviors, stealing or corrupting data maintained online or digitally, denial of service attacks on websites, "ransomware" that renders systems inoperable until ransom is paid, the unauthorized release of confidential information, or various other forms of cybersecurity breaches. Cyber-attacks affecting the Fund or the Adviser, custodian, transfer agent, distributor, administrator, intermediaries, trading counterparties, and other third-party service providers may adversely impact the Fund or the companies in which the Fund invests, causing the Fund's investments to lose value or to prevent a shareholder redemption or purchase from clearing in a timely manner. Debt Securities Risk. The Fund may invest in debt securities, including corporate bonds and high yield securities. In addition to the risks described elsewhere in this prospectus (such as high yield securities risk and interest rate risk), debt securities are subject to certain additional risks, including issuer risk and reinvestment risk. Issuer risk is the risk that the value of debt securities may decline for a number of reasons which directly relate to the issuer, such as management performance, leverage and reduced demand for the issuer's goods and services. Reinvestment risk is the risk that income from the Fund's portfolio will decline if the Fund invests the proceeds from matured, traded or called bonds at market interest rates that are below the Fund portfolio's current earnings rate. A decline in income could affect the market price of the Fund's common shares or the overall return of the Fund. Default Risk. Default risk refers to the risk that a company that issues a convertible or debt security will be unable to fulfill its obligations to repay principal and interest. The lower a debt security is rated, the greater its default risk. As a result, the Fund may incur cost and delays in enforcing its rights against the defaulting issuer. Derivatives Risk. Generally, derivatives are financial contracts whose value depends on, or is derived from, the value of an underlying asset, reference rate or index, and may relate to individual debt or equity instruments, interest rates, currencies or currency exchange rates, commodities, related indexes and other assets. The Fund may utilize a variety of derivative instruments including, but not limited to, interest rate swaps, caps and floors, convertible securities, synthetic convertible instruments, options on individual securities, index options, long calls, covered calls, long puts, cash-secured short puts and protective puts for hedging, risk management and investment purposes. The Fund's use of derivative instruments involves investment risks and transaction costs to which the Fund would not be subject absent the use of these instruments and, accordingly, may result in losses greater than if they had not been used. The use of derivative instruments may have risks including, among others, leverage risk, duration mismatch risk, correlation risk, liquidity risk, interest rate risk, volatility risk, credit risk, management risk and counterparty risk. Derivatives also involve the risk of mispricing or improper valuation and the risk that changes in the value of a derivative may not correlate perfectly with an underlying asset, interest rate or index. Suitable derivative transactions may not be available in all circumstances and there can be no assurance that the Fund will engage in these transactions to reduce exposure to other risks when that would be beneficial. Furthermore, the skills needed to employ derivatives strategies are different from those needed to select portfolio securities and, in connection with such strategies, the Fund makes predictions with respect to market conditions, liquidity, currency movements, market values, interest rates and other applicable factors, which may be inaccurate. Thus, the use of derivative instruments may require the Fund to sell or purchase portfolio securities at inopportune times or for prices below or above the current market values, may limit the amount of appreciation the Fund can realize on an investment or may cause the Fund to hold a security that it might otherwise want to sell. Tax rules governing the Fund's transactions in derivative instruments may also affect whether gains and losses recognized by the Fund are treated as ordinary or capital, accelerate the recognition of income or gains to the Fund, defer losses to the Fund, and cause adjustments in the holding periods of the Fund's securities, thereby affecting, among other things, whether capital gains and losses are treated as short-term or long-term. These rules could therefore affect the amount, timing and/or character of distributions to shareholders. In addition, there may be situations in which the Fund elects not to use derivative instruments that result in losses greater than if they had been used. Amounts paid by the Fund as premiums and cash or other assets held in margin accounts with respect to the Fund's derivative instruments would not be available to the Fund for other investment purposes, which may result in lost opportunities for gain. Derivative instruments can be illiquid, may disproportionately increase losses and may have a potentially large impact on Fund performance. Duration Risk. Duration measures the time-weighted expected cash flows of a fixed-income security, which can determine its sensitivity to changes in the general level of interest rates. The value of securities with longer durations tend to be more sensitive to interest rate changes than securities with shorter durations. The longer the Fund's dollar-weighted average duration, the more its value can generally be expected to be sensitive to interest rate changes than a fund with a shorter dollar-weighted average duration. Duration differs from maturity in that it considers a security's coupon payments in addition to the amount of time until the security matures. Various techniques may be used to shorten or lengthen the Fund's duration. As the value of a security changes over time, so will its duration. Duration Mismatch Risk. The duration of a derivative instrument may be significantly different than the duration of the related liability or asset. Emerging Markets Risk. Emerging market countries may have relatively unstable governments and economies based on only a few industries, which may cause greater instability. The value of emerging market securities will likely be particularly sensitive to changes in the economies of such countries. These countries are also more likely to experience higher levels of inflation, deflation or currency devaluations, which could adversely affect the value of the Fund's investments and hurt those countries' economies and securities markets. Securities issued in these countries may be more volatile and less liquid than securities issued in foreign countries with more developed economies or markets. Loss may also result from the imposition of exchange controls, confiscations and other government restrictions, or from problems in share registration, settlement, custody, or other operational risks. Equity Securities Risk. Equity investments are subject to greater fluctuations in market value than other asset classes as a result of such factors as the issuer's business performance, investor perceptions, stock market trends and general economic conditions. Equity securities are subordinated to bonds and other debt instruments in a company's capital structure in terms of priority to corporate income and liquidation payments. The Fund may invest in preferred stocks and convertible securities of any rating, including below investment grade. Below investment grade securities or comparable unrated securities are considered predominantly speculative with respect to the issuer's ability to pay interest and principal and are susceptible to default or decline in market value due to adverse economic and business developments. The market values for below investment grade securities tend to be very volatile, and these securities are generally less liquid than investment grade debt securities. For these reasons, your investment in the Fund is subject to the following specific risks: ● increased price sensitivity to changing interest rates and to a deteriorating economic environment; ● greater risk of loss due to default or declining credit quality; ● adverse company specific events are more likely to render the issuer unable to make interest and/or principal payments; and ● if a negative perception of the below investment grade market develops, the price and liquidity of below investment grade securities may be depressed. This negative perception could last for a significant period of time. Foreign Securities Risk. Investments in non-U.S. issuers may involve unique risks compared to investing in securities of U.S. issuers. These risks are more pronounced to the extent that the Fund invests a significant portion of its non-U.S. investments in one region or in the securities of emerging market issuers. See also " — Emerging Markets Risk" below. These risks may include: ● less information may be available about non-U.S. issuers or markets due to less rigorous disclosure or accounting standards or regulatory practices in foreign jurisdictions; ● many non-U.S. markets are smaller, less liquid and more volatile. In a changing market, Calamos may not be able to sell the Fund's portfolio securities at times, in amounts and at prices it considers reasonable; ● an adverse effect of currency exchange rate changes or controls on the value of the Fund's investments; ● the economies of non-U.S. countries may grow at slower rates than expected or may experience a downturn or recession; ● economic, political and social developments may adversely affect the securities markets in foreign jurisdictions, including expropriation and nationalization; ● the difficulty in obtaining or enforcing a court judgment in non-U.S. countries; ● restrictions on foreign investments in non-U.S. jurisdictions; ● difficulties in effecting the repatriation of capital invested in non-U.S. countries; ● withholding and other non-U.S. taxes may decrease the Fund's return; ● the ability for the Public Company Accounting Oversight Board, which regulates auditors of U.S. public companies, is unable to inspect audit work papers in certain foreign countries; ● often limited rights and few practical remedies to pursue shareholder claims, including class actions or fraud claims, and the ability of the Commission, the U.S. Department of Justice and other authorities to bring and enforce actions against foreign issuers or foreign persons is limited; and ● dividend income the Fund receives from foreign securities may not be eligible for the special tax treatment applicable to qualified dividend income. There may be less publicly available information about non-U.S. markets and issuers than is available with respect to U.S. securities and issuers. Non-U.S. companies generally are not subject to accounting, auditing and financial reporting standards, practices and requirements comparable to those applicable to U.S. companies. The trading markets for most non-U.S. securities are generally less liquid and subject to greater price volatility than the markets for comparable securities in the United States. The markets for securities in certain emerging markets are in the earliest stages of their development. Even the markets for relatively widely traded securities in certain non-U.S. markets, including emerging market countries, may not be able to absorb, without price disruptions, a significant increase in trading volume or trades of a size customarily undertaken by institutional investors in the United States. Additionally, market making and arbitrage activities are generally less extensive in such markets, which may contribute to increased volatility and reduced liquidity. Economies and social and political conditions in individual countries may differ unfavorably from those in the United States. Non-U.S. economies may have less favorable rates of growth of gross domestic product, rates of inflation, currency valuation, capital reinvestment, resource self-sufficiency and balance of payments positions. Many countries have experienced substantial, and in some cases extremely high, rates of inflation for many years. Inflation and rapid fluctuations in inflation rates have had, and may continue to have, very negative effects on the economies and securities markets of certain emerging market countries. Unanticipated political or social developments may also affect the values of the Fund's investments and the availability to the Fund of additional investments in such countries. Based upon the Fund's test for determining whether an issuer is a "foreign issuer" as described above, it is possible that an issuer of securities in which the Fund invests could be organized under the laws of a foreign country, yet still conduct a substantial portion of its business in the U.S. or have substantial assets in the U.S. In this case, such a "foreign issuer" may be subject to the market conditions in the U.S. to a greater extent than it may be subject to the market conditions in the country of its organization. See " — Non-U.S. Government Obligation Risk." Forward Currency Exchange Contracts Risk. Forward contracts are contractual agreements to purchase or sell a specified currency at a specified future date (or within a specified time period) at a price set at the time of the contract. The Fund may not fully benefit from, or may lose money on, forward foreign currency transactions if changes in currency exchange rates do not occur as anticipated or do not correspond accurately to changes in the value of the Fund's holdings. General Derivative Risks. Derivatives also involve the risk of mispricing or improper valuation and the risk that changes in the value of a derivative may not correlate perfectly with an underlying asset, interest rate or index. Suitable derivative transactions may not be available in all circumstances and there can be no assurance that the Fund will engage in these transactions to reduce exposure to other risks when that would be beneficial. Furthermore, the skills needed to employ derivatives strategies are different from those needed to select portfolio securities and, in connection with such strategies, the Fund makes predictions with respect to market conditions, liquidity, currency movements, market values, interest rates and other applicable factors, which may be inaccurate. Thus, the use of derivative investments may require the Fund to sell or purchase portfolio securities at inopportune times or for prices below or above the current market values, may limit the amount of appreciation the Fund can realize on an investment or may cause the Fund to hold a security that it might otherwise want to sell. Tax rules governing the Fund's transactions in derivative instruments may also affect whether gains and losses recognized by the Fund are treated as ordinary or capital, accelerate the recognition of income or gains to the Fund, defer losses to the Fund, and cause adjustments in the holding periods of the Fund's securities, thereby affecting, among other things, whether capital gains and losses are treated as short-term or long-term. These rules could therefore affect the amount, timing and/or character of distributions to shareholders. In addition, there may be situations in which the Fund elects not to use derivative instruments that result in losses greater than if they had been used. Amounts paid by the Fund as premiums and cash or other assets held in margin accounts with respect to the Fund's derivative instruments would not be available to the Fund for other investment purposes, which may result in lost opportunities for gain. Derivative instruments can be illiquid, and may disproportionately increase losses and may have a potentially large impact on Fund performance. Geographic Concentration Risk. Investments in a particular country or geographic region may be particularly susceptible to political, diplomatic or economic conditions and regulatory requirements. To the extent the Fund concentrates its investments in a particular country, region or group of regions, the Fund may be more volatile than a more geographically diversified fund. High Yield Securities Risk. The Fund may invest in high yield securities of any rating. Investment in high yield securities involves substantial risk of loss. Below investment grade non-convertible debt securities or comparable unrated securities are commonly referred to as "junk bonds" and are considered predominantly speculative with respect to the issuer's ability to pay interest and principal and are susceptible to default or decline in market value due to adverse economic and business developments. The market values for high yield securities tend to be very volatile, and these securities are less liquid than investment grade debt securities. For these reasons, your investment in the Fund is subject to the following specific risks: ● increased price sensitivity to changing interest rates and to a deteriorating economic environment; ● greater risk of loss due to default or declining credit quality; ● adverse company specific events are more likely to render the issuer unable to make interest and/or principal payments; and ● if a negative perception of the high yield market develops, the price and liquidity of high yield securities may be depressed. This negative perception could last for a significant period of time. Securities rated below investment grade are speculative with respect to the capacity of the issuer to pay interest and repay principal in accordance with the terms of such securities. A rating of "Ba1" from Moody's means that the issue so rated can have speculative elements and is subject to substantial credit risk. Standard & Poor's assigns a rating of "BB+" to issues that are less vulnerable to nonpayment than other speculative issues, but nonetheless subject to major ongoing uncertainties or exposure to adverse business, financial, or economic conditions which could lead to the obligor's inadequate capacity to meet its financial commitment on the obligation. A rating of "C" from Moody's means that the issue so rated can be regarded as having extremely poor prospects of ever attaining any real investment standing. Standard & Poor's assigns a rating of "C" to issues that are currently highly vulnerable to nonpayment, and the "C" rating may be used to cover a situation in which a bankruptcy petition has been filed or similar action taken, but payments on the obligation are being continued (a "C" rating is also assigned to a preferred stock issue in arrears on dividends or sinking fund payments, but that is currently paying). See the statement of additional information for a description of Moody's and Standard & Poor's ratings. Adverse changes in economic conditions are more likely to lead to a weakened capacity of a high yield issuer to make principal payments and interest payments than an investment grade issuer. The principal amount of high yield securities outstanding has proliferated in the past decade as an increasing number of issuers have used high yield securities for corporate financing. An economic downturn could severely affect the ability of highly leveraged issuers to service their debt obligations or to repay their obligations upon maturity. Similarly, downturns in profitability in specific industries could adversely affect the ability of high yield issuers in those industries to meet their obligations. The market values of lower quality debt securities tend to reflect individual developments of the issuer to a greater extent than do higher quality securities. Factors having an adverse impact on the market value of lower quality securities may have an adverse effect on the Fund's net asset value and the market value of its common shares. In addition, the Fund may incur additional expenses to the extent it is required to seek recovery upon a default in payment of principal or interest on its portfolio holdings. In certain circumstances, the Fund may be required to foreclose on an issuer's assets and take possession of its property or operations. In such circumstances, the Fund would incur additional costs in disposing of such assets and potential liabilities from operating any business acquired. The secondary market for high yield securities may not be as liquid as the secondary market for more highly rated securities, a factor which may have an adverse effect on the Fund's ability to dispose of a particular security. There are fewer dealers in the market for high yield securities than for investment grade obligations. The prices quoted by different dealers may vary significantly and the spread between the bid and asked price is generally much larger than for higher quality instruments. Under adverse market or economic conditions, the secondary market for high yield securities could contract further, independent of any specific adverse changes in the condition of a particular issuer, and these instruments may become illiquid. As a result, the Fund could find it more difficult to sell these securities or may be able to sell the securities only at prices lower than if such securities were widely traded. Prices realized upon the sale of such lower rated or unrated securities, under these circumstances, may be less than the prices used in calculating the Fund's NAV. Because investors generally perceive that there are greater risks associated with lower quality debt securities of the type in which the Fund may invest a portion of its assets, the yields and prices of such securities may tend to fluctuate more than those for higher rated securities. In the lower quality segments of the debt securities market, changes in perceptions of issuers' creditworthiness tend to occur more frequently and in a more pronounced manner than do changes in higher quality segments of the debt securities market, resulting in greater yield and price volatility. If the Fund invests in high yield securities that are rated "C" or below, the Fund will incur significant risk in addition to the risks associated with investments in high yield securities and corporate loans. Distressed securities frequently do not produce income while they are outstanding. The Fund may purchase distressed securities that are in default or the issuers of which are in bankruptcy. The Fund may be required to bear certain extraordinary expenses in order to protect and recover its investment. The Fund also will be subject to significant uncertainty as to when and in what manner and for what value the obligations evidenced by the distressed securities will eventually be satisfied. Inflation Risk. Inflation is the reduction in the purchasing power of money resulting from an increase in the price of goods and services. Inflation risk is the risk that the inflation adjusted or "real" value of an investment in preferred stock or debt securities or the income from that investment will be worth less in the future. As inflation occurs, the real value of the preferred stock or debt securities and the dividend payable to holders of preferred stock or interest payable to holders of debt securities declines. Interest Rate Risk. In addition to the risks described above, debt securities, including high yield securities, are subject to certain risks, including: ● if interest rates go up, the value of debt securities in the Fund's portfolio generally will decline; ● during periods of declining interest rates, the issuer of a security may exercise its option to prepay principal earlier than scheduled, forcing the Fund to reinvest in lower yielding securities. This is known as call or prepayment risk. Debt securities frequently have call features that allow the issuer to repurchase the security prior to its stated maturity. An issuer may redeem an obligation if the issuer can refinance the debt at a lower cost due to declining interest rates or an improvement in the credit standing of the issuer; ● during periods of rising interest rates, the average life of certain types of securities may be extended because of slower than expected principal payments. This may lock in a below market interest rate, increase the estimated period until the security is paid in full and reduce the value of the security. This is known as extension risk; ● rising interest rates could result in an increase in the cost of the Fund's leverage and could adversely affect the ability of the Fund to meet asset coverage requirements with respect to leverage; and ● variable rate securities generally are less sensitive to interest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as interest rates in general. When the Fund holds variable rate securities, a decrease in market interest rates will adversely affect the income received from such securities and the NAV of the Fund's shares. Benchmark Rate Risk and LIBOR Cessation. The London Interbank Offered Rate (“LIBOR”) was the offered rate for short-term Eurodollar deposits between major international banks. The terms of investments, financings or other transactions (including certain derivatives transactions) to which the Fund may be a party have historically been tied to LIBOR. In connection with the global transition away from LIBOR led by regulators and market participants, LIBOR was last published on a representative basis at the end of June 2023. Alternative reference rates to LIBOR have been established in most major currencies and the transition to new reference rates continues. Markets in these new rates are developing, but questions around liquidity and how to appropriately mitigate any economic value transfer as a result of the transition remain a concern. The transition away from LIBOR and the use of replacement rates may adversely affect transactions that used LIBOR as a reference rate, financial institutions, funds and other market participants that engaged in such transactions, and the financial markets generally. The impact of the transition away from LIBOR on the Fund or the financial instruments in which the Fund invests cannot yet be fully determined. In addition, interest rates or other types of rates and indices which are classed as “benchmarks” have been the subject of ongoing national and international regulatory reform, including under the European Union regulation on indices used as benchmarks in financial instruments and financial contracts (known as the “Benchmarks Regulation”). The Benchmarks Regulation has been enacted into United Kingdom law by virtue of the European Union (Withdrawal) Act 2018 (as amended), subject to amendments made by the Benchmarks (Amendment and Transitional Provision) (EU Exit) Regulations 2019 (SI 2019/657) and other statutory instruments. Following the implementation of these reforms, the manner of administration of benchmarks has changed and may further change in the future, with the result that relevant benchmarks may perform differently than in the past, the use of benchmarks that are not compliant with the new standards by certain supervised entities may be restricted, and certain benchmarks may be eliminated entirely. Additionally, there could be other consequences which cannot be predicted. As a result of the transition away from LIBOR as a benchmark reference for interest rates, certain bonds and loans held by the Fund may have floating interest rates based on SOFR or, if otherwise provided in the underlying contracts, other alternative benchmark rates. SOFR Risk. SOFR is a relatively new index rate calculated based on short-term repurchase agreements backed by U.S. Treasury Instruments. While LIBOR is an unsecured rate, SOFR is a secured rate. SOFR, unlike LIBOR, reflects actual market transactions. Accordingly, SOFR is not the economic equivalent of LIBOR. Consequently, there can be no assurance that SOFR will perform in the same way as LIBOR would have at any time, including, without limitation, as a result of changes in interest and yield rates in the market, monetary policy, bank credit risk, market volatility or global or regional economic, financial, political, regulatory, judicial or other events. Because SOFR is published by the Federal Reserve Bank of New York (the “New York Fed”) based on data received from other sources, the Adviser will have no control over its determination, calculation, or publication. There can be no assurance that SOFR will not be discontinued or fundamentally altered in a manner that is materially adverse to the interests of the Fund. If the manner in which SOFR is calculated is changed, that change may result in a reduction of the amount of interest payable on SOFR-linked floating rate instruments and the trading prices of such instruments. Additionally, daily changes in SOFR have, on occasion, been more volatile than daily changes in other benchmark or market rates. Although occasional, increased daily volatility in SOFR would not necessarily lead to more volatile interest payments, the return on and value of SOFR-linked floating rate instruments may fluctuate more than floating rate instruments that are linked to less volatile rates. All of the foregoing risks may affect the performance of the applicable bonds and loans in which the Fund invests, which in turn may adversely affect the performance of the Fund. Alternative Benchmark Rate Risk. As stated above, some of the bonds and loans held by the Fund may have floating interest rates based on alternative benchmark rates other than SOFR. Such alternative benchmark rates, like SOFR, may not have been widely used by market participants until relatively recently, and they may not perform exactly the same as LIBOR because they are calculated and administered differently. Generally, the use of alternative benchmark rates (including SOFR) may (i) cause the value of the interest rate on such bonds and loans to be uncertain or to be lower or more volatile than it would otherwise be, (ii) result in uncertainty as to the functioning, liquidity or value of such bonds and loans, and/or (iii) involve actions of regulators or rate administrators that may adversely affect certain markets or contracts underlying such bonds and loans. All of the foregoing could adversely affect the return on and value of the related floating rate instruments in which the Fund invests. Leverage Risk. The derivative instruments in which the Fund may invest will give rise to forms of financial leverage, which may magnify the risk of owning such instruments. Derivatives generally involve leverage in the sense that the investment exposure created by the derivatives may be significantly greater than the Fund’s initial investment in the derivative. Accordingly, if the Fund enters into a derivative transaction, it could lose substantially more than the principal amount invested. Additionally, as a closed-end investment company registered with the SEC, the Fund is subject to the federal securities laws, including the 1940 Act, the rules thereunder, and various SEC and SEC staff interpretive positions. In accordance with these laws, rules and positions, the Fund may “set aside” liquid assets (often referred to as “asset segregation”), or engage in other SEC or staff-approved measures, to “cover” open positions with respect to certain portfolio management techniques, such as engaging in reverse repurchase agreements, dollar rolls, entering into credit default swaps or futures contracts, or purchasing securities on a when-issued or delayed delivery basis, that may be considered senior securities under the 1940 Act. The Fund intends to cover its derivative positions by maintaining an amount of cash or liquid securities in a segregated account equal to the face value of those positions and by offsetting derivative positions against one another or against other assets to manage the effective market exposure resulting from derivatives in its portfolio. To the extent that the Fund does not segregate liquid assets or otherwise cover its obligations under such transactions, such transactions will be treated as senior securities representing indebtedness for purposes of the requirement under the 1940 Act that the Fund may not enter into any such transactions if the Fund’s borrowings would thereby exceed 33 1/3% of its managed assets, less all liabilities and indebtedness of the Fund not represented by senior securities. However, these transactions, even if covered, may represent a form of economic leverage and will create risks. In addition, these segregation and coverage requirements could result in the Fund maintaining securities positions that it would otherwise liquidate, segregating assets at a time when it might be disadvantageous to do so or otherwise restricting portfolio management. Such segregation and cover requirements will not limit or offset losses on related positions. The Fund has issued indebtedness and preferred shares and may borrow money or issue debt securities as permitted by the 1940 Act. As of January 31, 2025, the Fund has leverage in the form of borrowings under the SSB Agreement and outstanding MRP Shares. Leverage is the potential for the Fund to participate in gains and losses on an amount that exceeds the Fund's investment. The borrowing of money or issuance of debt securities and preferred shares represents the leveraging of the Fund's common shares. As a non-fundamental policy, the Fund may not issue preferred shares or borrow money and/or issue debt securities with an aggregate liquidation preference and aggregate principal amount exceeding 38% of the Fund's managed assets as measured at the time of borrowing or issuance of the new securities. However, the Board of Trustees reserves the right to issue preferred shares or debt securities or borrow to the extent permitted by the 1940 Act and the Fund's policies. See "Leverage." Leverage creates risks which may adversely affect the return for the holders of common shares, including: ● the likelihood of greater volatility in the NAV and market price of the Fund's common shares; ● fluctuations in the dividend rates on any preferred shares borne by the Fund or in interest rates on borrowings and short-term debt; ● increased operating costs, which are effectively borne by common shareholders, may reduce the Fund's total return; and ● the potential for a decline in the value of an investment acquired with borrowed funds, while the Fund's obligations under such borrowing or preferred shares remain fixed. In addition, the rights of lenders and the holders of preferred shares and debt securities issued by the Fund will be senior to the rights of the holders of common shares with respect to the payment of dividends or to the payment of assets upon liquidation. Holders of preferred shares have voting rights in addition to and separate from the voting rights of common shareholders. See "Description of Securities — Preferred Shares" and "Certain Provisions of the Agreement and Declaration of Trust and By-Laws, Including Antitakeover Provisions." The holders of preferred shares or debt, if any, on the one hand, and the holders of the common shares, on the other, may have interests that conflict in certain situations. The Fund's use of leverage is premised upon the expectation that the Fund's preferred share dividends or borrowing cost will be lower than the return the Fund achieves on its investments with the proceeds of the issuance of preferred shares or debt securities or borrowing. Such difference in return may result from the Fund's higher credit rating or the short-term nature of its borrowing compared to the lower credit quality, long-term nature of its investments. Because Calamos seeks to invest the Fund's managed assets (including the assets obtained from leverage) in a portfolio of potentially higher yielding investments or portfolio investments with the potential for capital appreciation, the holders of common shares will be the beneficiaries of any incremental return but will bear the risk of loss on investments made with the leverage proceeds. Should the differential between the Fund's return on its investments made with the proceeds of leverage and the cost of the leverage narrow, the incremental return "pick up" will be reduced or the Fund may incur losses. If long-term interest rates rise without a corresponding increase in the yield on the Fund's portfolio investments or the Fund otherwise incurs losses on its investments, the Fund's net asset value attributable to its common shareholders will reflect the decline in the value of portfolio holdings resulting therefrom. Leverage is a speculative technique that could adversely affect the returns to common shareholders. Leverage can cause the Fund to lose money and can magnify the effect of any losses. To the extent the income or capital appreciation derived from securities purchased with funds received from leverage exceeds the cost of leverage, the Fund's return will be greater than if leverage had not been used. Conversely, if the income or capital appreciation from the securities purchased with such funds is not sufficient to cover the cost of leverage or if the Fund incurs capital losses, the return of the Fund will be less than if leverage had not been used, and therefore the amount available for distribution to common shareholders as dividends and other distributions will be reduced or potentially eliminated. The Fund will pay, and common shareholders will effectively bear, any costs and expenses relating to any borrowings and to the issuance and ongoing maintenance of preferred shares or debt securities. Such costs and expenses include the higher management fee resulting from the use of any such leverage, offering and/or issuance costs, and interest and/or dividend expense and ongoing maintenance. These conditions may, directly or indirectly, result in higher leverage costs to common shareholders. Certain types of borrowings may result in the Fund being subject to covenants in credit agreements, including those relating to asset coverage, borrowing base and portfolio composition requirements and additional covenants that may affect the Fund's ability to pay dividends and distributions on common shares in certain instances. The Fund may also be required to pledge its assets to the lenders in connection with certain types of borrowings. The Fund may be subject to certain restrictions on investments imposed by guidelines of and covenants with rating agencies which may issue ratings for the preferred shares or short-term debt instruments issued by the Fund. These guidelines and covenants may impose asset coverage or portfolio composition requirements that are more stringent than those imposed by the 1940 Act. If the Fund's ability to make dividends and distributions on its common shares is limited, such limitation could, under certain circumstances, impair the ability of the Fund to maintain its qualification for taxation as a regulated investment company or to reduce or eliminate tax at the Fund level, which would have adverse tax consequences for common shareholders. To the extent that the Fund is required, in connection with maintaining 1940 Act asset coverage requirements or otherwise, or elects to redeem any preferred shares or debt securities or prepay any borrowings, the Fund may need to liquidate investments to fund such redemptions or prepayments. Liquidation at times of adverse economic conditions may result in capital loss and reduce returns to common shareholders. The Board reserves the right to change the amount and type of leverage that the Fund uses, and reserves the right to implement changes to the Fund's borrowings that it believes are in the long-term interests of the Fund and its shareholders, even if such changes impose a higher interest rate or other costs or impacts over the intermediate, or short-term time period. There is no guarantee that the Fund will maintain leverage at the current rate, and the Board reserves the right to raise, decrease, or eliminate the Fund's leverage exposure. See "Prospectus Summary — Use of Leverage by the Fund." Because Calamos' investment management fee is a percentage of the Fund's managed assets, Calamos' fee will be higher if the Fund is leveraged and Calamos will have an incentive to be more aggressive and leverage the Fund. Consequently, the Fund and Calamos may have differing interests in determining whether to leverage the Fund's assets. Any additional use of leverage by the Fund effected through new, additional or increased credit facilities or the issuance of preferred shares would require approval by the Board. In considering whether to approve the use of additional leverage, the Board would be presented with all relevant information necessary to make a determination whether or not additional leverage through those means would be in the best interests of the Fund, including information regarding any potential conflicts of interest. Liquidity Risk. The Fund may invest without limit in securities that, at the time of investment, are illiquid (i.e., any investment that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment). The Fund may also invest without limit in Rule 144A Securities determined to be liquid. Calamos, under the supervision and oversight of the Board of Trustees, will determine whether Rule 144A Securities are illiquid (that is, not readily marketable). Illiquid securities may be difficult to dispose of at a fair price at the times when the Fund believes it is desirable to do so. Investment of the Fund's assets in illiquid securities may restrict the Fund's ability to take advantage of market opportunities. The market price of illiquid securities generally is more volatile than that of more liquid securities, which may adversely affect the price that the Fund pays for or recovers upon the sale of illiquid securities. Illiquid securities are also more difficult to value and may be fair valued in which case Calamos' judgment may play a greater role in the valuation process. The risks associated with illiquid securities may be particularly acute in situations in which the Fund's operations require cash and could result in the Fund borrowing to meet its short-term needs or incurring losses on the sale of illiquid securities. The Fund may also invest without limitation in securities that have not been registered for public sale, but that are eligible for purchase and sale by certain qualified institutional buyers. Loan Risk. The Fund may invest in loans which may not be (i) rated at the time of investment, (ii) registered with the SEC or (iii) listed on a securities exchange. There may not be as much public information available regarding these loans as is available for other Fund investments, such as exchange-listed securities. As well, there may not be an active trading market for some loans, meaning they may be illiquid and more difficult to value than other more liquid securities. Settlement periods for loans are longer than for exchange-traded securities, typically ranging between 1 and 3 weeks, and in some cases much longer. There is no central clearinghouse for loan trades, and the loan market has not established enforceable settlement standards or remedies for failure to settle. Because the interest rates of floating-rate loans in which the Fund may invest may reset frequently, if market interest rates fall, the loans' interest rates will be reset to lower levels, potentially reducing the Fund's income. Because the adviser may wish to invest in the publicly-traded securities of an obligor, the Fund may not have access to material non-public information regarding the obligor to which other investors have access. Management Risk. Calamos' judgment about the attractiveness, relative value or potential appreciation of a particular sector, security or investment strategy may prove to be incorrect. Market Disruption Risk. Certain events have a disruptive effect on the securities markets, such as terrorist attacks, war and other geopolitical events, earthquakes, storms and other disasters. The Fund cannot predict the effects of similar events in the future on the U.S. economy or any foreign economy. High yield securities tend to be more volatile than higher rated debt securities so that these events and any actions resulting from them may have a greater impact on the prices and volatility of high yield securities than on higher rated securities. Master Limited Partnerships Risk. Investments in MLPs involve risks that differ from investments in common stock. Holders of MLP common units are subject to certain risks inherent in the structure of MLPs, including (i) tax risks, (ii) risk related to limited control of management or the general partner or managing member, (iii) limited rights to vote on matters affecting the MLP, except with respect to extraordinary transactions, (iv) conflicts of interest between the general partner or managing member and its affiliates, on the one hand, and the limited partners or members, on the other hand, including those arising from incentive distribution payments or corporate opportunities, and (v) cash flow risks. MLP common units and other equity securities can be affected by macro-economic and other factors affecting the stock market in general, expectations of interest rates, investor sentiment towards MLPs or the energy sector, changes in a particular issuer's financial condition, or unfavorable or unanticipated poor performance of a particular issuer (in the case of MLPs, generally measured in terms of distributable cash flow). Prices of common units of individual MLPs and other equity securities also can be affected by fundamentals unique to the partnership or company, including cash flow growth, cash generating power and distribution coverage. Although certain MLPs may trade on national securities exchanges, certain MLPs may trade less frequently than those of larger companies due to their market capitalizations. Due to limited trading volumes of certain MLPs, the prices of such MLPs may display abrupt or erratic movements at times. Additionally, it may be more difficult for the Fund to buy and sell significant amounts of such securities without an unfavorable impact on prevailing market prices. The Fund's investment in securities that are less actively traded or over time experience decreased trading volume may restrict its ability to dispose of the securities at a fair price. Such a situation may prevent the Fund from limiting losses or realizing gains. This also may adversely affect the Fund's ability to make dividend distributions to shareholders. MLPs are generally treated as partnerships for U.S. federal income tax purposes. Partnerships do not pay U.S. federal income tax at the partnership level. Rather, each partner is allocated a share of the partnership's income, gains, losses, deductions and expenses. A change in current tax law, or a change in the business of a given MLP, could result in an MLP being treated as a corporation for U.S. federal income tax purposes. As a result, the amount of cash available for distribution by the MLP would be reduced and the after-tax return to the Fund with respect to its investment in such MLPs would be materially reduced. Thus, if any of the MLPs owned by the Fund were treated as corporations for U.S. federal income tax purposes, it could result in a reduction in the value of the Fund. Maturity Risk. Interest rate risk will generally affect the price of a fixed income security more if the security has a longer maturity. Fixed income securities with longer maturities will therefore be more volatile than other fixed income securities with shorter maturities. Conversely, fixed income securities with shorter maturities will be less volatile but generally provide lower potential returns than fixed income securities with longer maturities. The average maturity of the Fund's investments may affect the volatility of the Fund's share price. Non-Convertible Income Securities Risk. The Fund will also invest in non-convertible income securities. The Fund's investments in non-convertible income securities may have fixed or variable principal payments and all types of interest rate and dividend payment and reset terms, including fixed rate, adjustable rate, zero coupon, contingent, deferred, payment in kind and auction rate features. Recent events in the fixed-income markets, including the potential impact of the Federal Reserve Board tapering its quantitative easing program, may expose the Fund to heightened interest rate risk and volatility. In addition, the Fund is subject to the risk that interest rates may exhibit increased volatility, which could cause the Fund's net asset value to fluctuate more. A decrease in fixed-income market maker capacity may act to decrease liquidity in the fixed-income markets and act to further increase volatility, affecting the Fund's return. Non-U.S. Government Obligation Risk. An investment in debt obligations of non-U.S. governments and their political subdivisions involves special risks that are not present in corporate debt obligations. The non-U.S. issuer of the sovereign debt or the non-U.S. governmental authorities that control the repayment of the debt may be unable or unwilling to repay principal or interest when due, and the Fund may have limited recourse in the event of a default. During periods of economic uncertainty, the market prices of sovereign debt may be more volatile than prices of debt obligations of U.S. issuers. Portfolio Selection Risk. The value of your investment may decrease if the investment adviser's judgment about the attractiveness, value or market trends affecting a particular security, issuer, industry or sector or about market movements is incorrect. Portfolio Turnover Risk. The portfolio managers may actively and frequently trade securities or other instruments in the Fund's portfolio to carry out its investment strategies. A high portfolio turnover rate increases transaction costs, which may increase the Fund's expenses. Frequent and active trading may also cause adverse tax consequences for investors in the Fund due to an increase in short-term capital gains. Recent Market Events. Since the 2008 financial crisis, financial markets throughout the world have experienced increased periods of volatility, depressed valuations, decreased liquidity and heightened uncertainty and turmoil. This turmoil resulted in unusual and extreme volatility in the equity and debt markets, in the prices of individual securities and in the world economy. Events that have contributed to these market conditions include, but are not limited to, major cybersecurity events, geopolitical events (such as wars (including Russia’s military invasion of Ukraine), terror attacks, natural or environmental disasters, country instability, and public health emergencies), measures to address budget deficits, downgrading of sovereign debt, dramatic changes in currency exchange rates, and public sentiment. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time. Widespread disease and virus epidemics and pandemics, such as the coronavirus outbreak, could likewise be highly disruptive, adversely affecting individual companies, sectors, industries, markets, currencies, interest and inflation rates, credit ratings, investor sentiment, and other factors affecting the value of the Fund's investments. Regulatory Risk. Derivatives markets are subject to various risks related to existing as well as new and evolving regulations both within and outside the United States. For example, in the United States, new or amended regulations may be imposed by the U.S. Commodity Futures Trading Commission (the “CFTC”), the SEC, the Federal Reserve or other financial regulators, other governmental regulatory authorities or self-regulatory organizations that supervise the financial markets that could adversely affect the Fund. In particular, these agencies are empowered to promulgate a variety of new rules pursuant to financial reform legislation in the United States. The Fund also may be adversely affected by changes in the enforcement or interpretation of existing statues and rules by these governmental regulatory authorities or self-regulatory organizations. In addition, the securities and futures markets are subject to comprehensive statutes, regulations and margin requirements. For instance, the Dodd — Frank Wall Street Reform and Consumer Protection Act of 2010 ("Dodd-Frank Act") could have an adverse effect on the Fund's ability to use derivative instruments. The Dodd-Frank Act is designed to impose stringent regulation on the over-the-counter derivatives market in an attempt to increase transparency and accountability and provides for, among other things, clearing, execution, margin, reporting, recordkeeping, business conduct, disclosure, position limit, minimum net capital and registration requirements. Because regulations that are being implemented by these requirements are evolving (and some of the regulations are not yet final), their ultimate impact remains unclear. Similar requirements are in the process of being implemented in the European Union, the United Kingdom and other jurisdictions which may impact the Fund’s transactions with entities domiciled in such jurisdictions and subject to such requirements. These regulations could, among other things, restrict the Fund's ability to engage in derivatives transactions (for example, by making certain types of derivatives transactions no longer available to our funds), increase the costs of using these instruments (for example, by increasing margin, capital or reporting requirements) and/or make them less effective and, as a result, the Fund may be unable to execute its investment strategy. Limits or restrictions applicable to the counterparties with which the Fund engages in derivative transactions could also prevent the Fund from using these instruments, affect the pricing or other factors relating to these instruments or may change availability of certain investments. It is unclear how the regulatory changes will affect counterparty risk. Rule 18f-4 under the 1940 Act provides for the regulation of registered investment companies' use of derivatives and certain related instruments. The rule, among other things, limits derivatives exposure through one of two value-at-risk tests, requires funds to adopt and implement a derivatives risk management program (including the appointment of a derivatives risk manager and the implementation of certain testing requirements), and subjects funds to certain reporting requirements in respect of derivatives. Limited derivatives users (as determined by Rule 18f-4) are not, however, subject to the full requirements under the rule. Rule 18f-4 could restrict the Fund's ability to engage in certain derivatives transactions and/or increase the costs of such derivatives transactions, which could adversely affect the value or performance of the Fund. REIT Risk. Investing in real estate investment trusts (“REITs”) involves certain unique risks in addition to those risks associated with investing in the real estate industry in general. An equity REIT may be affected by changes in the value of the underlying properties owned by the REIT. A mortgage REIT may be affected by changes in interest rates and the ability of the issuers of its portfolio mortgages to repay their obligations. REITs are dependent upon the skills of their managers and are not diversified. REITs are generally dependent upon maintaining cash flows to repay borrowings and to make distributions to shareholders and are subject to the risk of default by lessees or borrowers. REITs whose underlying assets are concentrated in properties used by a particular industry, such as health care, are also subject to risks associated with such industry. REITs (especially mortgage REITs) are also subject to interest rate risks. When interest rates decline, the value of a REIT's investment in fixed rate obligations can be expected to rise. Conversely, when interest rates rise, the value of a REIT's investment in fixed rate obligations can be expected to decline. If the REIT invests in adjustable rate mortgage loans the interest rates on which are reset periodically, yields on a REIT's investments in such loans will gradually align themselves to reflect changes in market interest rates. This causes the value of such investments to fluctuate less dramatically in response to interest rate fluctuations than would investments in fixed rate obligations. REITs may have limited financial resources, may utilize significant amounts of leverage, may trade less frequently and in a limited volume and may be subject to more abrupt or erratic price movements than larger company securities. Historically, REITs have been more volatile in price than the larger capitalization stocks included in Standard & Poor's 500 Stock Index. Risks Associated with Options. The Fund may use options, including on the Fund's convertible securities or during the creation of synthetic convertible instruments. There are several risks associated with transactions in options. For example, there are significant differences between the securities markets and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. A decision as to whether, when and how to use options involves the exercise of skill and judgment, and even a well-conceived transaction may be unsuccessful to some degree because of market behavior or unexpected events. The Fund's ability to utilize options successfully will depend on Calamos' ability to predict pertinent market movements, which cannot be assured. The Fund intends to seek to generate income from option premiums by writing (selling) options. The Fund may write (sell) call options (i) on a portion of the equity securities (including securities that are convertible into equity securities) in the Fund's portfolio, (ii) on a portion of the equity securities the Fund has a right to receive upon conversion of a convertible security that it owns at the time it writes the call, and (iii) on broad-based securities indices (such as the S&P 500 or MSCI EAFE) or certain ETFs that trade like common stocks but seek to replicable such market indices. All call options sold by the Fund must be "covered." For example, a call option written by the Fund will require the Fund to hold the securities subject to the call (or securities convertible into the needed securities without additional consideration) or to segregate cash or liquid assets sufficient to purchase and deliver the securities if the call is exercised. Even though the Fund will receive the option premium to help protect it against loss, a call option sold by the Fund exposes the Fund during the term of the option to possible loss of opportunity to realize appreciation in the market price of the underlying security or instrument and may require the Fund to hold a security or instrument that it might otherwise have sold. The Fund may purchase and sell put options on individual securities and securities indices. In selling put options, there is a risk that the Fund may be required to buy the underlying security at a disadvantageous price above the market price. Rule 144A Securities Risk. The Fund may invest in securities that are issued and sold through transactions under Rule 144A of the Securities Act of 1933. Under the supervision and oversight of the Board of Trustees, Calamos will determine whether Rule 144A Securities are illiquid. If qualified institutional buyers are unwilling to purchase these Rule 144A Securities, the percentage of the Fund's assets invested in illiquid securities would increase. Typically, the Fund purchases Rule 144A Securities only if the Fund's adviser has determined them to be liquid. If any Rule 144A Security held by the Fund should become illiquid, the value of the security may be reduced and a sale of the security may be more difficult. Sector Risk. To the extent the Fund invests a significant portion of its assets in a particular sector, a greater portion of the Fund's performance may be affected by the general business and economic conditions affecting that sector. Each sector may share economic risk with the broader market, however there may be economic risks specific to each sector. As a result, returns from those sectors may trail returns from the overall stock market and it is possible that the Fund may underperform the broader market, or experience greater volatility. Synthetic Convertible Instruments Risk. The value of a synthetic convertible instrument may respond differently to market fluctuations than a convertible instrument because a synthetic convertible instrument is composed of two or more separate securities, each with its own market value. In addition, if the value of the underlying common stock or the level of the index involved in the convertible component falls below the exercise price of the warrant or option, the warrant or option may lose all value. Synthetic convertible instruments created by other parties have the same attributes of a convertible security; however, the issuer of the synthetic convertible instrument assumes the credit risk associated with the investment, rather than the issuer of the underlying equity security into which the instrument is convertible. Investing in synthetic convertible instruments also involves the risk that the Fund does not achieve the investment exposure desired by Calamos. The Fund remains subject to the credit risk associated with the counterparty creating the synthetic convertible instrument. Tax Risk. The Fund may invest in certain securities, such as certain convertible securities and high yield securities, for which the federal income tax treatment may not be clear or may be subject to recharacterization by the IRS. It could be more difficult for the Fund to comply with certain federal income tax requirements applicable to regulated investment companies if the tax characterization of the Fund's investments is not clear or if the tax treatment of the income from such investments was successfully challenged by the IRS. Any failure to comply with the rules applicable to regulated investment companies could cause the Fund to fail to qualify as such. In addition, the tax treatment of the Fund may be affected by future interpretations of the Code and changes in the tax laws and regulations, all of which may apply with retroactive effect. See "Certain Federal Income Tax Matters." Certain of the Fund's investment practices may be subject to special and complex federal income tax provisions that may, among other things, (i) disallow, suspend or otherwise limit the allowance of certain losses or deductions, (ii) convert tax-advantaged, long-term capital gains and qualified dividend income into higher taxed short-term capital gain or ordinary income, (iii) increase ordinary income distributions, (iv) convert an ordinary loss or a deduction into a capital loss (the deductibility of which is more limited), (v) cause the Fund to recognize income or gain without a corresponding receipt of cash, (vi) adversely affect the timing as to when a purchase or sale of stock or securities is deemed to occur, and (vii) adversely alter the characterization of certain complex financial transactions. The Fund will monitor its transactions and may make certain tax elections where applicable in order to mitigate the effect of these provisions, if possible. U.S. Government Security Risk. Some securities issued by U.S. Government agencies or government sponsored enterprises are not backed by the full faith and credit of the U.S. and may only be supported by the right of the agency or enterprise to borrow from the U.S. Treasury. There can be no assurance that the U.S. Government will always provide financial support to those agencies or enterprises. Volatility Risk. Risk may arise in connection with the use of derivative instruments from volatility of interest rates and the prices of reference instruments. Additional Risks to Common Shareholders Generally, an investment in common shares is subject to the following risks: Diminished Voting Power and Excess Cash Risk. The voting power of current shareholders will be diluted to the extent that such shareholders do not purchase shares in any future common share offerings or do not purchase sufficient shares to maintain their percentage interest. In addition, if the Fund is unable to invest the proceeds of such offering as intended, its per share distribution may decrease (or may consist of return of capital) and the Fund may not participate in market advances to the same extent as if such proceeds were fully invested as planned. Interest Rate Transactions Risk. The Fund may enter into an interest rate swap, cap or floor transaction to attempt to protect itself from increasing dividend or interest expenses on its leverage resulting from increasing short-term interest rates and to hedge its portfolio securities. A decline in interest rates may result in a decline in the value of the swap or cap, which may result in a decline in the net asset value of the Fund. Depending on the state of interest rates in general, the Fund's use of interest rate swap or cap transactions could enhance or harm the overall performance of the common shares. To the extent there is a decline in interest rates, the value of the interest rate swap or cap could decline, and could result in a decline in the net asset value of the common shares. In addition, if the counterparty to an interest rate swap or cap defaults, the Fund would not be able to use the anticipated net receipts under the swap or cap to offset the dividend or interest payments on the Fund's leverage or offset certain losses in its portfolio. Depending on whether the Fund would be entitled to receive net payments from the counterparty on the swap or cap, which in turn would depend on the general state of short-term interest rates at that point in time, such a default could negatively impact the performance of the common shares. In addition, at the time an interest rate swap or cap transaction reaches its scheduled termination date, there is a risk that the Fund would not be able to obtain a replacement transaction or that the terms of the replacement would not be as favorable as on the expiring transaction. If either of these events occurs, it could have a negative impact on the performance of the common shares. If the Fund fails to maintain a required 200% asset coverage of the liquidation value of any outstanding preferred shares or if the Fund loses its rating on its preferred shares or fails to maintain other covenants with respect to the preferred shares, the Fund may be required to redeem some or all of the preferred shares. Similarly, the Fund could be required to prepay the principal amount of any debt securities or other borrowings. Such redemption or prepayment would likely result in the Fund seeking to terminate early all or a portion of any swap or cap transaction. Early termination of a swap could result in a termination payment by or to the Fund. Early termination of a cap could result in a termination payment to the Fund. The Fund intends to segregate with its custodian cash or liquid securities having a value at least equal to the Fund's net payment obligations under any swap transaction, marked-to-market daily. Currently, certain categories of interest rate swaps are subject to mandatory clearing, and more are expected to be cleared in the future. The counterparty risk for cleared derivatives is generally lower than for uncleared OTC derivative transactions because generally a clearing organization becomes substituted for each counterparty to a cleared derivative contract and, in effect, guarantees the parties' performance under the contract as each party to a trade looks only to the clearing house for performance of financial obligations. However, there can be no assurance that a clearing house, or its members, will satisfy the clearing house's obligations to the Fund. Market Discount Risk. The Fund's common shares have traded both at a premium and at a discount relative to net asset value. Common shares of closed-end investment companies frequently trade at a discount from net asset value, but in some cases trade above net asset value. The risk of the Fund's common shares trading at a discount is a risk separate from the risk of a decline in the Fund's net asset value as a result of investment activities. The Fund's net asset value may be reduced immediately following this offering by the offering costs for common shares or other securities, which will be borne entirely by all common shareholders. Whether shareholders will realize a gain or loss upon the sale of the Fund's common shares depends upon whether the market value of the shares at the time of sale is above or below the price the shareholder paid, taking into account transaction costs for the shares, and is not directly dependent upon the Fund's net asset value. Because the market value of the Fund's common shares will be determined by factors such as the relative demand for and supply of the shares in the market, general market conditions and other factors beyond the control of the Fund, the Fund cannot predict whether its common shares will trade at, below or above the Fund's net asset value, or below or above the public offering price for the common shares. Market Impact Risk. The sale of our common shares (or the perception that such sales may occur) may have an adverse effect on prices in the secondary market for our common shares. An increase in the number of common shares available may put downward pressure on the market price for our common shares. These sales also might make it more difficult for us to sell additional equity securities in the future at a time and price the Fund deems appropriate. Reduction of Leverage Risk. We have previously taken, and may in the future take, action to reduce the amount of leverage employed by the Fund. Reduction of the leverage employed by the Fund, including by redemption of preferred shares, will in turn reduce the amount of assets available for investment in portfolio securities. This reduction in leverage may negatively impact our financial performance, including our ability to sustain current levels of distributions on common shares. The Board reserves the right to change the amount and type of leverage that the Fund uses, and reserves the right to implement changes to the Fund's borrowings that it believes are in the best long-term interests of the Fund and its shareholders, even if such changes impose a higher interest rate or other costs or impacts over the intermediate, or short-term time period. There is no guarantee that the Fund will maintain leverage at the current rate, and the Board reserves the right to raise, decrease, or eliminate the Fund's leverage exposure. Additional Risks to Senior Security Holders Additional risks of investing in senior securities include the following: Generally, an investment in preferred shares (including exchange-listed preferred shares) or debt securities (collectively, "senior securities") is subject to the following risks: Decline in Net Asset Value Risk. A material decline in the Fund's NAV may impair our ability to maintain required levels of asset coverage for outstanding borrowings or any debt securities or preferred shares. Early Redemption Risk. The Fund may voluntarily redeem preferred shares or may be forced to redeem preferred shares to meet regulatory requirements and the asset coverage requirements of the preferred shares. Such redemptions may be at a time that is unfavorable to holders of the preferred shares. Inflation Risk. Inflation is the reduction in the purchasing power of money resulting from an increase in the price of goods and services. Inflation risk is the risk that the inflation adjusted or "real" value of an investment in preferred stock or debt securities or the income from that investment will be worth less in the future. As inflation occurs, the real value of the preferred stock or debt securities and the dividend payable to holders of preferred stock or interest payable to holders of debt securities declines. Interest Rate Risk. Rising market interest rates could impact negatively the value of our investment portfolio, reducing the amount of assets serving as asset coverage for the senior securities. Rising market interest rates could also reduce the value of the Fund's senior securities. Market Discount Risk. The market price of exchange-listed preferred shares that the Fund may issue may also be affected by such factors as the Fund's use of leverage, dividend stability, portfolio credit quality, liquidity, and the Fund's dividends paid (which are, in turn, affected by expenses), call protection for portfolio securities and interest rate movements. Ratings and Asset Coverage Risk. To the extent that senior securities are rated, a rating does not eliminate or necessarily mitigate the risks of investing in our senior securities, and a rating may not fully or accurately reflect all of the credit and market risks associated with that senior security. A rating agency could downgrade the rating of our shares of preferred stock or debt securities, which may make such securities less liquid in the secondary market, though potentially with higher resulting interest rates. If a rating agency downgrades the rating assigned to a senior security, we may alter our portfolio or redeem the senior security. We may voluntarily redeem senior securities under certain circumstances. Secondary Market Risk. The market value of exchange-listed preferred shares that the Fund may issue will be determined by factors such as the relative demand for and supply of the preferred shares in the market, general market conditions and other factors beyond the control of the Fund. It may be difficult to predict the trading patterns of preferred shares, including the effective costs of trading. There is a risk that the market for preferred shares may be thinly traded and relatively illiquid compared to the market for other types of securities. Senior Leverage Risk. Preferred shares will be junior in liquidation and with respect to distribution rights to debt securities and any other borrowings. Senior securities representing indebtedness may constitute a substantial lien and burden on preferred shares by reason of their prior claim against our income and against our net assets in liquidation. We may not be permitted to declare dividends or other distributions with respect to any series of preferred shares unless at such time we meet applicable asset coverage requirements and the payment of principal or interest is not in default with respect to any borrowings. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Effects of Leverage [Text Block] |  | Effects of Leverage The SSB Agreement provides for credit availability for the Fund, such that it may borrow up to $430 million. As of January 31, 2025, the Fund had utilized $315 million of the $430 million available under the SSB Agreement ($253 million in advances outstanding, and $62 million in structural leverage consisting of collateral received from counterparties via SSB in connection with securities on loan), representing 25.6% of the Fund's managed assets as of that date, and had $133 million of MRP Shares outstanding, representing 10.8% of the Fund's managed assets. Combined, the borrowings under the SSB Agreement and the outstanding MRP Shares represented 36.4% of the Fund's managed assets. Interest on the SSB Agreement is charged on the drawn amount at the rate of the Overnight Bank Financing Rate (OBFR) plus 0.52%, payable monthly in arrears. Interest on overdue amounts or interest on the drawn amount paid during an event of default will be charged at OBFR plus 2.52%. These rates represent floating rates of interest that may change over time. The SSB Agreement also provides that if the Fund restricts SSB’s ability to lend securities to multiple otherwise eligible counterparties that, on a historical basis, have accounted for more than 25% up to 50% of the Fund’s historical securities lending transactions, the borrowing cost under the SSB Agreement will increase by .25% per annum, and that if the Fund restricts SSB’s ability to lend securities to multiple otherwise eligible counterparties that, on a historical basis, have accounted for more than 50% of the Fund’s historical securities lending transactions, the borrowing cost under the SSB Agreement will increase by 0.45% per annum, comprising Further, if the Fund restricts securities comprising more than 5% of its total assets from being available to lend for purposes of the securities lending program (excluding certain categories of ordinary course restrictions or as otherwise agreed by SSB), the costs of leverage to the Fund will be increased by 0.20% per annum. The SSB Agreement has a commitment fee of 0.10% of any undrawn amount. As of January 31, 2025, the interest rate charged under the SSB Agreement was 5.35%. The Fund's MRP Shareholders are entitled to receive monthly cash dividends, at a currently effective dividend rate per annum for each series of MRP Shares as follows (subject to adjustment as described above in "Mandatory Redeemable Preferred Shares"): 4.24% for Series C MRP Shares, 2.45% for Series DMRP Shares, 2.68% for Series E MRP Shares and 6.24% for Series G MRP Shares. To cover the interest expense on the borrowings under the SSB Agreement and the dividend payments associated with the MRP Shares, based on rates in effect on January 31, 2025, the Fund's portfolio would need to experience an annual return of 1.71% (before giving effect to expenses associated with senior securities). Leverage is a speculative technique that could adversely affect the returns to common shareholders. Leverage can cause the Fund to lose money and can magnify the effect of any losses. To the extent the income or capital appreciation derived from securities purchased with funds received from leverage exceeds the cost of leverage, the Fund's return will be greater than if leverage had not been used. Conversely, if the income or capital appreciation from the securities purchased with such funds is not sufficient to cover the cost of leverage or if the Fund incurs capital losses, the return of the Fund will be less than if leverage had not been used, and therefore the amount available for distribution to common shareholders as dividends and other distributions will be reduced or potentially eliminated. The Fund will pay, and common shareholders will effectively bear, any costs and expenses relating to any borrowings and to the issuance and ongoing maintenance of preferred shares, including the MRP Shares, or debt securities. Such costs and expenses include the higher management fee resulting from the use of any such leverage, offering and/or issuance costs, and interest and/or dividend expense and ongoing maintenance. Certain types of borrowings may result in the Fund being subject to covenants in credit agreements, including those relating to asset coverage, borrowing base and portfolio composition requirements and additional covenants that may affect the Fund's ability to pay dividends and distributions on common shares in certain instances. The Fund may also be required to pledge its assets to the lenders in connection with certain types of borrowings. The Fund may be subject to certain restrictions on investments imposed by guidelines of and covenants with rating agencies for the preferred shares or short-term debt instruments issued by the Fund. These guidelines and covenants may impose asset coverage or portfolio composition requirements that are more stringent than those imposed by the 1940 Act. Because Calamos' investment management fee is a percentage of the Fund's managed assets, Calamos' fee will be higher if the Fund is leveraged and Calamos will have an incentive to be more aggressive and leverage the Fund. Consequently, the Fund and Calamos may have differing interests in determining whether to leverage the Fund's assets. Any additional use of leverage by the Fund effected through new, additional or increased credit facilities or the issuance of preferred shares would require approval by the Board of Trustees of the Fund. The following table illustrates the hypothetical effect on the return to a holder of the Fund's common shares of the leverage obtained by us (and utilized on January 31, 2025). The purpose of this table is to assist you in understanding the effects of leverage. As the table shows, leverage generally increases the return to common shareholders when portfolio return is positive and greater than the cost of leverage and decreases the return when the portfolio return is negative or less than the cost of leverage. The figures appearing in the table are hypothetical and actual returns may be greater or less than those appearing in the table.
Assumed Portfolio Return (Net of Expenses) |  |  | (10.00 | )% |  |  | (5.00 | )% |  |  | 0.00 | % |  |  | 5.00 | % |  |  | 10.00 | %
Corresponding Common Share Return(1) |  |  | (18.41 | )% |  |  | (10.55 | )% |  |  | (2.69 | )% |  |  | 5.17 | % |  |  | 13.03 | %
(1) Includes interest expense on the borrowings under the SSB Agreement, accrued at interest rates in effect on January 31, 2025 of 5.35%, and dividend expense on the MRP Shares. For further information about leveraging, see "Risk Factors — Fund Risks — Leverage Risk." |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Annual Dividend Payment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (1.14) |  | (1.14) |  | (1.14) | (1.1) | (0.96) | (0.96) | (1.13) | (1.14) | (1.14) | (1.14) |
Annual Interest Rate [Percent] |  |  | 1.71% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Annual Interest Rate, Current [Percent] |  |  | 5.35% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Effects of Leverage [Table Text Block] |  |
Assumed Portfolio Return (Net of Expenses) |  |  | (10.00 | )% |  |  | (5.00 | )% |  |  | 0.00 | % |  |  | 5.00 | % |  |  | 10.00 | %
Corresponding Common Share Return(1) |  |  | (18.41 | )% |  |  | (10.55 | )% |  |  | (2.69 | )% |  |  | 5.17 | % |  |  | 13.03 | %
(1) Includes interest expense on the borrowings under the SSB Agreement, accrued at interest rates in effect on January 31, 2025 of 5.35%, and dividend expense on the MRP Shares. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Return at Minus Ten [Percent] | [9] | (18.41%) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Return at Minus Five [Percent] | [9] | (10.55%) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Return at Zero [Percent] | [9] | (2.69%) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Return at Plus Five [Percent] | [9] | 5.17% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Return at Plus Ten [Percent] | [9] | 13.03% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Effects of Leverage, Purpose [Text Block] |  | The following table illustrates the hypothetical effect on the return to a holder of the Fund's common shares of the leverage obtained by us (and utilized on January 31, 2025). The purpose of this table is to assist you in understanding the effects of leverage. As the table shows, leverage generally increases the return to common shareholders when portfolio return is positive and greater than the cost of leverage and decreases the return when the portfolio return is negative or less than the cost of leverage. The figures appearing in the table are hypothetical and actual returns may be greater or less than those appearing in the table. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share Price [Table Text Block] |  | The following table sets forth for each of the periods indicated the high and low closing market prices for our common shares on Nasdaq, the NAV per share and the premium or discount to NAV per share at which our common shares were trading. NAV is shown for the last business day of each quarter. See "Net Asset Value" for information as to the determination of our NAV.
|  | Market Price(1) |  |  | Net Asset Value at Quarter |  |  | Premium/ (Discount) to Net Asset Value(3) |
Quarter Ended |  | High |  |  | Low |  |  | End(2) |  |  | High |  |  | Low |
January 31, 2025 |  | $ | 12.28 |  |  | $ | 11.19 |  |  | $ | 10.25 |  |  |  | 22.85 | % |  |  | 10.59 | %
October 31, 2024 |  | $ | 12.01 |  |  | $ | 10.91 |  |  | $ | 10.04 |  |  |  | 18.20 | % |  |  | 13.13 | %
July 31, 2024 |  | $ | 12.02 |  |  | $ | 11.04 |  |  | $ | 9.95 |  |  |  | 20.24 | % |  |  | 11.61 | %
April 30, 2024 |  | $ | 11.54 |  |  | $ | 10.55 |  |  | $ | 9.74 |  |  |  | 14.21 | % |  |  | 7.46 | %
January 31, 2024 |  | $ | 10.71 |  |  | $ | 9.74 |  |  | $ | 10.00 |  |  |  | 12.00 | % |  |  | 0.41 | %
October 31, 2023 |  | $ | 11.32 |  |  | $ | 10.00 |  |  | $ | 8.99 |  |  |  | 15.20 | % |  |  | 4.56 | %
July 31, 2023 |  | $ | 11.36 |  |  | $ | 9.90 |  |  | $ | 10.51 |  |  |  | 10.21 | % |  |  | 1.53 | %
April 30, 2023 |  | $ | 12.34 |  |  | $ | 10.21 |  |  | $ | 9.94 |  |  |  | 16.91 | % |  |  | 1.49 | %
January 31, 2023 |  | $ | 12.09 |  |  | $ | 10.51 |  |  | $ | 10.61 |  |  |  | 15.03 | % |  |  | 3.89 | %
Source: Fund Accounting Records. (1) Based on high and low closing market price per share during the respective quarter and does not reflect commissions. (2) Based on the NAV calculated on the close of business on the last business day of each calendar quarter. (3) Premium and discount information is shown for the days when the Fund experienced its high and low closing market prices, respectively, per share during the respective quarter. The last reported sale price, NAV per common share and percentage premium to NAV per common share on January 31, 2025 were $11.37, $10.25 and 10.93%, respectively. As of January 31, 2025, we had 76,312,702 common shares outstanding and managed assets of $1.2 billion. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Lowest Price or Bid | [10] |  |  |  | $ 11.19 |  | 10.91 |  | $ 11.04 |  | $ 10.55 |  | $ 9.74 |  | 10 |  | $ 9.9 |  | $ 10.21 |  | $ 10.51 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Highest Price or Bid | [10] |  |  |  | $ 12.28 |  | $ 12.01 |  | $ 12.02 |  | $ 11.54 |  | $ 10.71 |  | $ 11.32 |  | $ 11.36 |  | $ 12.34 |  | $ 12.09 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Highest Price or Bid, Premium (Discount) to NAV [Percent] | [11] |  |  |  | 22.85% |  | 18.20% |  | 20.24% |  | 14.21% |  | 12.00% |  | 15.20% |  | 10.21% |  | 16.91% |  | 15.03% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Lowest Price or Bid, Premium (Discount) to NAV [Percent] | [11] |  |  |  | 10.59% |  | 13.13% |  | 11.61% |  | 7.46% |  | 0.41% |  | 4.56% |  | 1.53% |  | 1.49% |  | 3.89% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share Price |  |  | $ 11.37 |  | $ 11.37 |  | $ 11.43 |  |  |  |  |  |  |  | $ 9.99 |  |  |  |  |  |  |  | 11.43 |  | 9.99 |  | 10.78 | 15.81 | 10.89 | 10.67 | 9.91 | 11.59 | 9.89 | 10.41 |
NAV Per Share |  |  | $ 10.25 | [12] | $ 10.25 | [12] | $ 10.04 | [12] | $ 9.95 | [12] | $ 9.74 | [12] | $ 10 | [12] | $ 8.99 | [12] | $ 10.51 | [12] | $ 9.94 | [12] | $ 10.61 | [12] | $ 10.04 | [12] | $ 8.99 | [12] | $ 10.26 | $ 15.49 | $ 12.54 | $ 10.64 | $ 10.46 | $ 11.35 | $ 10.73 | $ 11.68 | $ 13.45
Latest Premium (Discount) to NAV [Percent] |  |  | 10.93% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital Stock, Long-Term Debt, and Other Securities [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital Stock [Table Text Block] |  | DESCRIPTION OF SECURITIES The following is a brief description of the capital structure of the Fund. This description does not purport to be complete and is subject to and qualified in its entirety by reference to the Fund's Agreement and Declaration of Trust and By-Laws, each as amended and restated through the date hereof. The Agreement and Declaration of Trust and By-Laws are each exhibits to the registration statement of which this prospectus is a part. The Fund is authorized to issue an unlimited number of common shares, without par value. The Fund is also authorized to issue preferred shares and debt securities. As of January 31, 2025, the Fund had 76,312,702 common shares outstanding and MRP Shares outstanding in the following amounts: 1,340,000 Series C MRP Shares, 1,320,000 Series D MRP Shares, 1,330,000 Series E MRP Shares, and 1,320,000 Series G MRP Shares. As of such date, the Fund had not issued any debt securities. Subject to the restrictions under the 1940 Act, the Board of Trustees may, from time to time, establish additional series or classes of Fund shares and set forth the designations, preferences, conversion or other rights, voting powers, restrictions, limitations as to dividends, qualifications or terms or conditions of redemption of such shares and pursuant to such classification or reclassification to increase or decrease the number of authorized shares of any existing class or series but the Board may not change any outstanding shares in a manner materially adverse to such shareholders. The Board of Trustees, without shareholder approval but subject to the governing documents of the Fund and the MRP Shares, is authorized to amend the Agreement and Declaration of Trust and By-Laws to reflect the terms of any such class or series. As of January 31, 2025, the Fund had total leverage of approximately $448 million representing approximately 36.4% of the Fund's managed assets as of that date. The Fund will pay, and common shareholders will effectively bear, any costs and expenses relating to any borrowings by the Fund, including the financial leverage described above, as well as any additional leverage incurred as a result of this offering. Such costs and expenses include the higher management fee resulting from the use of any such leverage, offering and/or issuance costs, and interest and/or dividend expense and ongoing maintenance. Borrowings under the SSB Agreement are secured by assets of the Fund that are held with the Fund's custodian in a separate account. Interest on the SSB Agreement is charged on the drawn amount at the rate of OBFR plus 0.52%, payable monthly in arrears. Interest on overdue amounts or interest on the drawn amount paid during an event of default will be charged at OBFR plus 2.52%. The SSB Agreement has a commitment fee of 0.10% of any undrawn amount. The SSB Agreement also provides that if the Fund restricts SSB’s ability to lend securities to multiple otherwise eligible counterparties that, on a historical basis, have accounted for lending comprising more than 25% up to 50% of the value of securities on loan, the Fund’s cost of leverage will be increased by 0.25% per annum. If the Fund restricts SSB’s ability to lend securities to multiple otherwise eligible counterparties that, on a historical basis, have accounted for lending comprising over 50% of the value of securities on loan, the Fund’s cost of leverage will be increased by 0.45% per annum, Further, if the Fund restricts securities comprising more than 5% of its total assets from being available to lend for purposes of the securities lending program (excluding ordinary course restrictions and as otherwise agreed by SSB), the costs of leverage to the Fund will be increased by 0.20% per annum. As of January 31, 2025, the net interest rate charged under the SSB Agreement was 5.35%. Under the terms of the SSB Agreement, all securities lent or subject to repurchase transactions through SSB must be secured continuously by collateral received in cash. Cash collateral received by SSB on behalf of the Fund is deposited into a custodial account in the name of the Fund before being treated as refinancing a portion of the amounts borrowed under the SSB Agreement. The cost of leverage to the Fund under the SSB Agreement is the same, regardless of whether funded as an advance from SSB or by securities lending agented by SSB. Any amounts credited against the borrowings under the SSB Agreement would count against the Fund's leverage limitations under the 1940 Act. Under the terms of the SSB Agreement, the Fund is required to return the value of the collateral to the borrower upon the return of the lent securities, which will eliminate the credit against the borrowings under the SSB Agreement and will increase the balance on which the Fund will pay interest. The Fund reserves the right to utilize sources of borrowings in addition to, or in lieu of, the SSB Agreement. See "Prospectus Summary — Use of Leverage by the Fund." While unsecured and unsubordinated indebtedness may rank equally with the borrowings under the SSB Agreement in right of payment, the lender under the agreement, together with the holders of other outstanding secured indebtedness, may, to the exclusion of unsecured creditors, seek recourse against the collateral as security for the borrowings and such other secured indebtedness until amounts owed under the SSB Agreement and the other secured indebtedness are satisfied in full. All borrowings under the SSB Agreement and the securities lending agreement rank senior to the Fund's common and preferred shares as to the payment of interest and distribution of assets upon liquidation. The securities lending arrangement with SSB involves characteristics common in arm’s length relationships in which one party may benefit at the expense of the other party. A declaration of a dividend or other distribution on or purchase or redemption of any common or preferred shares of the Fund may be prohibited (i) at any time that an event of default under any borrowings has occurred and is continuing, or (ii) if after giving effect to such declaration, purchase or redemption, the Fund would not meet the 1940 Act asset coverage requirements or any temporary requirements imposed under an order issued by the SEC. Common Shares Common shares, when issued and outstanding, will be legally issued, fully paid and non-assessable and will have no preemptive or conversion rights or rights to cumulative voting, except as described below. The Board has not granted such common shares conversion rights. Shareholders are entitled to share pro rata in the net assets of the Fund available for distribution to common shareholders upon liquidation of the Fund. Common shareholders are entitled to one vote for each share held. The Fund's Agreement and Declaration of Trust provides that the Trustees have the power to cause each shareholder to pay directly, in advance or arrears, for charges of the Fund's custodian or transfer, shareholder servicing or similar agent, an amount fixed from time to time by the Trustees, by setting off such charges due from a shareholder from declared but unpaid dividends owed to such shareholder and/or by reducing the number of shares in the account of such shareholder. So long as any preferred shares that may be issued by the Fund are outstanding, holders of common shares will not be entitled to receive any net income of or other distributions from the Fund unless all accumulated dividends on preferred shares have been paid, and unless asset coverage (as defined in the 1940 Act) with respect to preferred shares would be at least 200% after giving effect to such distributions. See "Leverage." The Fund will provide unaudited semi-annual financial statements and audited annual financial statements to all of its shareholders. Other offerings of common shares, if made, will require approval of the Board of Trustees and will be subject to the requirement of the 1940 Act that common shares may not be sold at a price below the then-current net asset value, exclusive of underwriting discounts and commissions, except in limited circumstances including in connection with an offering to existing shareholders. Common shares may be sold in one or more at the market offerings through sales on Nasdaq at a price equal to or above the Fund's per share NAV plus any sales commissions paid by the Fund to execute such sales. Preferred Shares Preferred shares, when issued and outstanding, will be legally issued, fully paid and non-assessable. Holders of preferred shares will be entitled to the rights and preferences set out in the documents creating the preferred shares. As a non-fundamental policy, the Fund may not issue preferred shares or borrow money and/or issue debt securities with an aggregate liquidation preference and aggregate principal amount exceeding 38% of the Fund's managed assets. However, the Board of Trustees reserves the right to issue preferred shares to the extent permitted by the 1940 Act, which currently limits the aggregate liquidation preference of all outstanding preferred shares to 50% of the value of the Fund's total assets less the Fund's liabilities and indebtedness not represented by senior securities. Under the 1940 Act, the Fund may only issue one class of preferred shares. So long as any preferred shares are outstanding, additional issuances of preferred shares may not have preference or priority over the outstanding preferred shares. In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Fund, the holders of preferred shares will be entitled to receive a preferential liquidating distribution, which is expected to equal the original purchase price per preferred share plus accumulated and unpaid dividends, whether or not declared, before any distribution of assets is made to holders of common shares. After payment of the full amount of the liquidating distribution to which they are entitled, the holders of preferred shares will not be entitled to any further participation in any distribution of assets by the Fund. The 1940 Act requires that the holders of any preferred shares, voting separately as a single class, have the right to elect at least two Trustees at all times. The remaining Trustees will be elected by holders of common shares and preferred shares, voting together as a single class. In addition, subject to the prior rights, if any, of the holders of any other class of senior securities outstanding, the holders of any preferred shares have the right to elect a majority of the Trustees at any time two years' accumulated dividends on any preferred shares are unpaid. The 1940 Act also requires that, in addition to any approval by shareholders that might otherwise be required, the approval of the holders of a majority of any outstanding preferred shares, voting separately as a class, would be required to (1) adopt any plan of reorganization that would adversely affect the preferred shares, and (2) take any action requiring a vote of security holders under Section 13(a) of the 1940 Act, including, among other things, changes in the Fund's subclassification as a closed-end investment company or changes in its fundamental investment restrictions. See "Certain Provisions of the Agreement and Declaration of Trust and By-Laws, Including Antitakeover Provisions." As a result of these voting rights, the Fund's ability to take any such actions may be impeded to the extent that there are any preferred shares outstanding. Except as otherwise indicated in this prospectus and except as otherwise required by applicable law, holders of preferred shares have equal voting rights with holders of common shares (one vote per share, unless otherwise required by the 1940 Act) and will vote together with holders of common shares as a single class. The affirmative vote of the holders of a majority of the outstanding preferred shares, voting as a separate class, will be required to amend, alter or repeal any of the preferences, rights or powers of holders of preferred shares so as to affect materially and adversely such preferences, rights or powers, or to increase or decrease the authorized number of preferred shares. The class vote of holders of preferred shares described above will in each case be in addition to any other vote required to authorize the action in question. Any redemption or purchase of any preferred shares by the Fund will reduce the leverage applicable to the common shares, while any resale of shares by the Fund will increase that leverage. Preferred shares that may be issued by the Fund may or may not be listed on an exchange or automated quotation system. The details on how to buy and sell such securities, along with the other terms of the securities, will be described in a prospectus supplement. We cannot assure you that any market will exist for our preferred securities or if a market does exist, whether it will provide holders with liquidity. Debt Securities General. Under Delaware law and the Fund's Agreement and Declaration of Trust, it may borrow money, without prior approval of holders of common and preferred shares. The Fund may issue debt securities, or other evidence of indebtedness (including bank borrowings or commercial paper) and may secure any such notes or borrowings by mortgaging, pledging or otherwise subjecting as security our assets to the extent permitted by the 1940 Act or rating agency guidelines. Any borrowings will rank senior to preferred shares and the common shares. Under the 1940 Act, the Fund may only issue one class of senior securities representing indebtedness other than promissory notes or other evidences of indebtedness not intended to be publicly distributed, which in the aggregate, may represent no more than 33 1/3% of our managed assets. A prospectus supplement and indenture (a summary of the expected terms of which is attached as Appendix A to the statement of additional information) relating to any debt securities will include specific terms relating to the offering. These terms are expected to include the following: ● the form and title of the security; ● the aggregate principal amount of the securities; ● the interest rate of the securities; ● the maturity dates on which the principal of the securities will be payable; ● any changes to or additional events of default or covenants; ● any optional or mandatory redemption provisions; ● identities of, and any changes in trustees, paying agents or security registrar; and ● any other terms of the securities. Interest. Unless otherwise stated in a prospectus supplement, debt securities will bear interest as generally determined by the Board of Trustees, as more fully described in the related prospectus supplement. Interest on debt securities shall be payable when due as described in the related prospectus supplement. If we do not pay interest when due, it will trigger an event of default and we will be restricted from declaring dividends and making other distributions with respect to our common shares and preferred shares. Limitations. Under the requirements of the 1940 Act, immediately after issuing any senior securities representing indebtedness, we must have an asset coverage of at least 300%. Asset coverage means the ratio which the value of our total assets, less all liabilities and indebtedness not represented by senior securities, bears to the aggregate amount of senior securities representing indebtedness. Other types of borrowings also may result in our being subject to similar covenants in credit agreements. Events of Default and Acceleration of Maturity of Debt Securities; Remedies. Unless stated otherwise in the related prospectus supplement, any one of the following events are expected to constitute an "event of default" for that series under the indenture: ● default in the payment of any interest upon a series of debt securities when it becomes due and payable and the continuance of such default for 30 days; ● default in the payment of the principal of, or premium on, a series of debt securities at its stated maturity; ● default in the performance, or breach, of any covenant or warranty of ours in the indenture, and continuance of such default or breach for a period of 90 days after written notice has been given to us by the trustee; ● certain voluntary or involuntary proceedings involving us and relating to bankruptcy, insolvency or other similar laws; ● if, on the last business day of each of twenty-four consecutive calendar months, the debt securities have a 1940 Act asset coverage of less than 100%; or ● any other "event of default" provided with respect to a series, including a default in the payment of any redemption price payable on the redemption date. Upon the occurrence and continuance of an event of default, the holders of a majority in principal amount of a series of outstanding debt securities or the trustee may declare the principal amount of that series of debt securities immediately due and payable upon written notice to us. A default that relates only to one series of debt securities does not affect any other series and the holders of such other series of debt securities are not entitled to receive notice of such a default under the indenture. Upon an event of default relating to bankruptcy, insolvency or other similar laws, acceleration of maturity occurs automatically with respect to all series. At any time after a declaration of acceleration with respect to a series of debt securities has been made, and before a judgment or decree for payment of the money due has been obtained, the holders of a majority in principal amount of the outstanding debt securities of that series, by written notice to us and the trustee, may rescind and annul the declaration of acceleration and its consequences if all events of default with respect to that series of debt securities, other than the non-payment of the principal of that series of debt securities which has become due solely by such declaration of acceleration, have been cured or waived and other conditions have been met. Liquidation Rights. In the event of (a) any insolvency or bankruptcy case or proceeding, or any receivership, liquidation, reorganization or other similar case or proceeding in connection therewith, relative to us or to our creditors, as such, or to our assets, or (b) any liquidation, dissolution or other winding up of the Fund, whether voluntary or involuntary and whether or not involving insolvency or bankruptcy, or (c) any assignment for the benefit of creditors or any other marshalling of assets and liabilities of ours, then (after any payments with respect to any secured creditor of ours outstanding at such time) and in any such event the holders of debt securities shall be entitled to receive payment in full of all amounts due or to become due on or in respect of all debt securities (including any interest accruing thereon after the commencement of any such case or proceeding), or provision shall be made for such payment in cash or cash equivalents or otherwise in a manner satisfactory to the holders of the debt securities, before the holders of any common or preferred stock of the Fund are entitled to receive any payment on account of any redemption proceeds, liquidation preference or dividends from such shares. The holders of debt securities shall be entitled to receive, for application to the payment thereof, any payment or distribution of any kind or character, whether in cash, property or securities, including any such payment or distribution which may be payable or deliverable by reason of the payment of any other indebtedness of ours being subordinated to the payment of the debt securities, which may be payable or deliverable in respect of the debt securities in any such case, proceeding, dissolution, liquidation or other winding up event. Unsecured creditors of ours may include, without limitation, service providers including Calamos, the Fund's custodian, the Fund's administrator, broker-dealers and the trustee, pursuant to the terms of various contracts with us. Secured creditors of ours may include without limitation SSB and other lenders to the Fund, parties entering into any interest rate swap, floor or cap transactions, or other similar transactions with us that create liens, pledges, charges, security interests, security agreements or other encumbrances on our assets. A consolidation, reorganization or merger of the Fund with or into any other company, or a sale, lease or exchange of all or substantially all of our assets in consideration for the issuance of equity securities of another company shall not be deemed to be a liquidation, dissolution or winding up of the Fund. Voting Rights. Debt securities have no voting rights, except to the extent required by law or as otherwise provided in the indenture relating to the acceleration of maturity upon the occurrence and continuance of an event of default. In connection with any other borrowings (if any), the 1940 Act does in certain circumstances grant to the lenders certain voting rights in the event of default in the payment of interest on or repayment of principal. Market. Our debt securities are not likely to be listed on an exchange or automated quotation system. The details on how to buy and sell such securities, along with the other terms of the securities, will be described in a prospectus supplement. We cannot assure you that any market will exist for our debt securities or if a market does exist, whether it will provide holders with liquidity. Book-Entry, Delivery and Form. Unless otherwise stated in the related prospectus supplement, the debt securities will be issued in book-entry form and will be represented by one or more notes in registered global form. The global notes will be deposited with the trustee as custodian for The Depository Trust Company ("DTC") and registered in the name of Cede & Co., as nominee of DTC. DTC will maintain the notes in designated denominations through its book-entry facilities. Under the expected terms of the indenture, we and the trustee may treat the persons in whose names any notes, including the global notes, are registered as the owners thereof for the purpose of receiving payments and for any and all other purposes whatsoever. Therefore, so long as DTC or its nominee is the registered owner of the global notes, DTC or such nominee will be considered the sole holder of outstanding notes under the indenture. We or the trustee may give effect to any written certification, proxy or other authorization furnished by DTC or its nominee. A global note may not be transferred except as a whole by DTC, its successors or their respective nominees. Interests of beneficial owners in the global note may be transferred or exchanged for definitive securities in accordance with the rules and procedures of DTC. In addition, a global note may be exchangeable for notes in definitive form if: ● DTC notifies us that it is unwilling or unable to continue as a depository and we do not appoint a successor within 60 days; ● we, at our option, notify the trustee in writing that we elect to cause the issuance of notes in definitive form under the indenture; or ● an event of default has occurred and is continuing. In each instance, upon surrender by DTC or its nominee of the global note, notes in definitive form will be issued to each person that DTC or its nominee identifies as being the beneficial owner of the related notes. Under the expected terms of the indenture, the holder of any global note may grant proxies and otherwise authorize any person, including its participants and persons who may hold interests through DTC participants, to take any action which a holder is entitled to take under the indenture. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Securities [Table Text Block] |  |  | The following table provides information about our outstanding securities as of January 31, 2025:
Title of Class |  | Amount Authorized (shares) |  |  | Amount Held by the Fund or for its Account |  |  | Amount Outstanding (shares) |
Common Shares |  |  | Unlimited |  |  |  | 0 |  |  |  | 76,312,702 |
MRPS-Series C |  |  | 1,340,000 |  |  |  | 0 |  |  |  | 1,340,000 |
MRPS-Series D |  |  | 1,320,000 |  |  |  | 0 |  |  |  | 1,320,000 |
MRPS-Series E |  |  | 1,330,000 |  |  |  | 0 |  |  |  | 1,330,000 |
MRPS-Series G |  |  | 1,320,000 |  |  |  | 0 |  |  |  | 1,320,000 |
Outstanding Security, Not Held [Shares] |  |  | 76,312,702 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | General. The Fund is a diversified, closed-end management investment company designed primarily as a long-term investment and not as a trading tool. The Fund invests primarily in a diversified portfolio of convertible securities and non-convertible income securities. An investment in the Fund's common shares may be speculative and it involves a high degree of risk. The Fund is not a complete investment program. Due to the uncertainty in all investments, there can be no assurance that the Fund will achieve its investment objective. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
American Depositary Receipts Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | American Depositary Receipts Risk. The stocks of most foreign companies that trade in the U.S. markets are traded as ADRs. U.S. depositary banks issue these stocks. Each ADR represents one or more shares of foreign stock or a fraction of a share. The price of an ADR corresponds to the price of the foreign stock in its home market, adjusted to the ratio of the ADRs to foreign company shares. Therefore, while purchasing a security on a U.S. exchange, the risks inherently associated with foreign investing still apply to ADRs. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Antitakeover Provisions Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Antitakeover Provisions. The Fund's Agreement and Declaration of Trust and By-Laws include provisions that could limit the ability of other entities or persons to acquire control of the Fund or to change the composition of its Board of Trustees. Such provisions could limit the ability of shareholders to sell their shares at a premium over prevailing market prices by discouraging a third party from seeking to obtain control of the Fund. These provisions include staggered terms of office for the Trustees, advance notice requirements for shareholder proposals, and super-majority voting requirements for certain transactions with affiliates, converting the Fund to an open-end investment company or a merger, asset sale or similar transaction. Holders of preferred shares have voting rights in addition to and separate from the voting rights of common shareholders with respect to certain of these matters. Holders of any preferred shares, voting separately as a single class, have the right to elect at least two Trustees at all times. See "Description of Securities — Preferred Shares" and "Certain Provisions of the Agreement and Declaration of Trust and By-Laws, Including Antitakeover Provisions." The holders of preferred shares or debt, if any, on the one hand, and the holders of the common shares, on the other, may have interests that conflict with each other in certain situations, including conflicts that relate to the fees and expenses of the Fund. For more information on potential conflicts of interest between holders of common shares and holders of preferred shares, see "Leverage Risk" above. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash Holdings Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Cash Holdings Risk. To the extent the Fund holds cash positions, the Fund risks achieving lower returns and potential lost opportunities to participate in market appreciation which could negatively impact the Fund's performance and ability to achieve its investment objective. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Contingent Liabilities Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Contingent Liabilities Risk. Entering into derivative contracts in order to pursue the Fund's various hedging strategies could require the Fund to fund cash payments in the future under certain circumstances, including an event of default or other early termination event, or the decision by a counterparty to request margin in the form of securities or other forms of collateral under the terms of the derivative contract or applicable laws. The amounts due with respect to a derivative contract would generally be equal to the unrealized loss of the open positions with the respective counterparty and could also include other fees and charges. These payments are contingent liabilities and therefore may not appear on the Fund's balance sheet. The Fund's ability to fund these contingent liabilities will depend on the liquidity of the Fund's assets and access to capital at the time, and the need to fund these contingent liabilities could adversely impact our financial condition. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Convertible Hedging And Short Sales Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Convertible Securities Risk. The value of a convertible security is influenced by both the yield of non-convertible securities of comparable issuers and by the value of the underlying common stock. The value of a convertible security viewed without regard to its conversion feature (i.e., strictly on the basis of its yield) is sometimes referred to as its "investment value." A convertible security's investment value tends to decline as prevailing interest rate levels increase. Conversely, a convertible security's investment value tends to increase as prevailing interest rate levels decline. However, a convertible security's market value tends to reflect the market price of the common stock of the issuing company when that stock price is greater than the convertible security's "conversion price." The conversion price is defined as the predetermined price at which the convertible security could be exchanged for the associated stock. As the market price of the underlying common stock declines, the price of the convertible security tends to be influenced more by the yield of the convertible security and changes in interest rates. Thus, the convertible security may not decline in price to the same extent as the underlying common stock. In the event of a liquidation of the issuing company, holders of convertible securities would be paid before the company's common stockholders. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Correlation Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Correlation Risk. Imperfect correlation between the value of derivative instruments and the underlying assets of the Fund creates the possibility that the loss on such instruments may be greater than the gain in the value of the underlying assets in the Fund's portfolio. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Counterparty and Settlement Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Counterparty and Settlement Risk. Trading options, futures contracts, swaps and other derivative financial instruments entails credit risk with respect to the counterparties with whom and through which the Fund trades. Such instruments when traded over the counter do not include the same protections as may apply to trading derivatives on organized exchanges. Substantial losses may arise from the insolvency, bankruptcy or default of a counterparty and risk of settlement default of parties with whom the Fund trades securities. This risk may be heightened during volatile market conditions. Settlement mechanisms in emerging markets are generally less developed and reliable than those in more developed countries thus increasing the risks. In the past, broker-dealers and other financial institutions have experienced extreme financial difficulty, sometimes resulting in bankruptcy of the institution. Although Calamos monitors the creditworthiness of the Fund's counterparties, there can be no assurance that the Fund's counterparties will not experience similar difficulties, possibly resulting in losses to the Fund. If a counterparty becomes bankrupt or otherwise fails to perform its obligations under a derivative contract due to financial difficulties, such bankruptcy or failure to perform is likely to result in a default under such derivative contract, unless such default is cured. Default by a party with whom the Fund enters into a hedging transaction may result in the loss of unrealized profits, leaving the Fund with unsecured exposure and force the Fund to cover its resale commitments, if any, at the then current market price. It may not always be possible to dispose of or close out a hedging position without the consent of the hedging counterparty, and the Fund may not be able to enter into an offsetting contract in order to cover its risk. The Fund cannot assure its shareholders that a liquid secondary market will exist for hedging instruments purchased or sold, and the Fund may be required to maintain a position until exercise or expiration, which could result in losses. Furthermore, upon the bankruptcy of a counterparty, the Fund may experience significant delays in obtaining any recovery under the derivative contract in a dissolution, assignment for the benefit of creditors, liquidation, winding-up, bankruptcy, or other analogous proceeding. In addition, in the event of the insolvency of a counterparty to a derivative transaction, the derivative transaction would typically be terminated at its fair market value. If the Fund is owed this fair market value in the termination of the derivative transaction and its claim is unsecured, the Fund will be treated as a general creditor of such counterparty, and will not have any claim with respect to the underlying security. The Fund may obtain only a limited recovery or may obtain no recovery in such circumstances and the enforceability of agreements for hedging transactions may depend on compliance with applicable statutory and other regulatory requirements and, depending on the identity of the counterparty, applicable international requirements. Certain interest rate and credit default swaps are subject to mandatory clearing, in which case a central clearing counterparty stands between each buyer and seller and effectively guarantees performance of each derivative contract, to the extent of its available resources for such purpose. As a result, the counterparty risk is now shifted from bilateral risk between the parties to the individual credit risk of the central clearing counterparty and the futures commission merchant through which the Fund holds its cleared position. Even in such case, there can be no assurance that a clearing house, or its members, will satisfy the clearing house's obligations to the Fund. Uncleared derivatives have no such protection; each party bears the risk that its direct counterparty will default. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Covenant Lite Loans Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | "Covenant-Lite" Loans Risk. Some of the loans in which the Fund may invest may be "covenant-lite" loans, which means the loans contain fewer or no maintenance covenants than other loans and do not include terms which allow the lender to monitor the performance of the borrower and declare a default if certain criteria are breached. The Fund may experience delays in enforcing its rights on its holdings of covenant-lite loans. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Credit Risks [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Credit Risk. An issuer of a fixed income security could be downgraded or default. If the Fund holds securities that have been downgraded, or that default on payment, the Fund's performance could be negatively affected. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Currency Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Currency Risk. To the extent that the Fund invests in securities or other instruments denominated in or indexed to foreign currencies, changes in currency exchange rates bring an added dimension of risk. Currency fluctuations could negatively impact investment gains or add to investment losses. Although the Fund may attempt to hedge against currency risk, the hedging instruments may not always perform as the Fund expects and could produce losses. Suitable hedging instruments may not be available for currencies of emerging market countries. The Fund's investment adviser may determine not to hedge currency risks, even if suitable instruments appear to be available. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cybersecurity Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Cybersecurity Risk. Investment companies, such as the Fund, and their service providers are exposed to operational and information security risks resulting from cyberattacks, which may result in financial losses to a fund and its shareholders. Cyber-attacks include, among other behaviors, stealing or corrupting data maintained online or digitally, denial of service attacks on websites, "ransomware" that renders systems inoperable until ransom is paid, the unauthorized release of confidential information, or various other forms of cybersecurity breaches. Cyber-attacks affecting the Fund or the Adviser, custodian, transfer agent, distributor, administrator, intermediaries, trading counterparties, and other third-party service providers may adversely impact the Fund or the companies in which the Fund invests, causing the Fund's investments to lose value or to prevent a shareholder redemption or purchase from clearing in a timely manner. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Securities Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Debt Securities Risk. The Fund may invest in debt securities, including corporate bonds and high yield securities. In addition to the risks described elsewhere in this prospectus (such as high yield securities risk and interest rate risk), debt securities are subject to certain additional risks, including issuer risk and reinvestment risk. Issuer risk is the risk that the value of debt securities may decline for a number of reasons which directly relate to the issuer, such as management performance, leverage and reduced demand for the issuer's goods and services. Reinvestment risk is the risk that income from the Fund's portfolio will decline if the Fund invests the proceeds from matured, traded or called bonds at market interest rates that are below the Fund portfolio's current earnings rate. A decline in income could affect the market price of the Fund's common shares or the overall return of the Fund. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Default Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Default Risk. Default risk refers to the risk that a company that issues a convertible or debt security will be unable to fulfill its obligations to repay principal and interest. The lower a debt security is rated, the greater its default risk. As a result, the Fund may incur cost and delays in enforcing its rights against the defaulting issuer. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivatives Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Derivatives Risk. Generally, derivatives are financial contracts whose value depends on, or is derived from, the value of an underlying asset, reference rate or index, and may relate to individual debt or equity instruments, interest rates, currencies or currency exchange rates, commodities, related indexes and other assets. The Fund may utilize a variety of derivative instruments including, but not limited to, interest rate swaps, caps and floors, convertible securities, synthetic convertible instruments, options on individual securities, index options, long calls, covered calls, long puts, cash-secured short puts and protective puts for hedging, risk management and investment purposes. The Fund's use of derivative instruments involves investment risks and transaction costs to which the Fund would not be subject absent the use of these instruments and, accordingly, may result in losses greater than if they had not been used. The use of derivative instruments may have risks including, among others, leverage risk, duration mismatch risk, correlation risk, liquidity risk, interest rate risk, volatility risk, credit risk, management risk and counterparty risk. Derivatives also involve the risk of mispricing or improper valuation and the risk that changes in the value of a derivative may not correlate perfectly with an underlying asset, interest rate or index. Suitable derivative transactions may not be available in all circumstances and there can be no assurance that the Fund will engage in these transactions to reduce exposure to other risks when that would be beneficial. Furthermore, the skills needed to employ derivatives strategies are different from those needed to select portfolio securities and, in connection with such strategies, the Fund makes predictions with respect to market conditions, liquidity, currency movements, market values, interest rates and other applicable factors, which may be inaccurate. Thus, the use of derivative instruments may require the Fund to sell or purchase portfolio securities at inopportune times or for prices below or above the current market values, may limit the amount of appreciation the Fund can realize on an investment or may cause the Fund to hold a security that it might otherwise want to sell. Tax rules governing the Fund's transactions in derivative instruments may also affect whether gains and losses recognized by the Fund are treated as ordinary or capital, accelerate the recognition of income or gains to the Fund, defer losses to the Fund, and cause adjustments in the holding periods of the Fund's securities, thereby affecting, among other things, whether capital gains and losses are treated as short-term or long-term. These rules could therefore affect the amount, timing and/or character of distributions to shareholders. In addition, there may be situations in which the Fund elects not to use derivative instruments that result in losses greater than if they had been used. Amounts paid by the Fund as premiums and cash or other assets held in margin accounts with respect to the Fund's derivative instruments would not be available to the Fund for other investment purposes, which may result in lost opportunities for gain. Derivative instruments can be illiquid, may disproportionately increase losses and may have a potentially large impact on Fund performance. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Duration Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Duration Risk. Duration measures the time-weighted expected cash flows of a fixed-income security, which can determine its sensitivity to changes in the general level of interest rates. The value of securities with longer durations tend to be more sensitive to interest rate changes than securities with shorter durations. The longer the Fund's dollar-weighted average duration, the more its value can generally be expected to be sensitive to interest rate changes than a fund with a shorter dollar-weighted average duration. Duration differs from maturity in that it considers a security's coupon payments in addition to the amount of time until the security matures. Various techniques may be used to shorten or lengthen the Fund's duration. As the value of a security changes over time, so will its duration. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Duration Mismatch Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Duration Mismatch Risk. The duration of a derivative instrument may be significantly different than the duration of the related liability or asset. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Emerging Markets Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Emerging Markets Risk. Emerging market countries may have relatively unstable governments and economies based on only a few industries, which may cause greater instability. The value of emerging market securities will likely be particularly sensitive to changes in the economies of such countries. These countries are also more likely to experience higher levels of inflation, deflation or currency devaluations, which could adversely affect the value of the Fund's investments and hurt those countries' economies and securities markets. Securities issued in these countries may be more volatile and less liquid than securities issued in foreign countries with more developed economies or markets. Loss may also result from the imposition of exchange controls, confiscations and other government restrictions, or from problems in share registration, settlement, custody, or other operational risks. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity Securities Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Equity Securities Risk. Equity investments are subject to greater fluctuations in market value than other asset classes as a result of such factors as the issuer's business performance, investor perceptions, stock market trends and general economic conditions. Equity securities are subordinated to bonds and other debt instruments in a company's capital structure in terms of priority to corporate income and liquidation payments. The Fund may invest in preferred stocks and convertible securities of any rating, including below investment grade. Below investment grade securities or comparable unrated securities are considered predominantly speculative with respect to the issuer's ability to pay interest and principal and are susceptible to default or decline in market value due to adverse economic and business developments. The market values for below investment grade securities tend to be very volatile, and these securities are generally less liquid than investment grade debt securities. For these reasons, your investment in the Fund is subject to the following specific risks: ● increased price sensitivity to changing interest rates and to a deteriorating economic environment; ● greater risk of loss due to default or declining credit quality; ● adverse company specific events are more likely to render the issuer unable to make interest and/or principal payments; and ● if a negative perception of the below investment grade market develops, the price and liquidity of below investment grade securities may be depressed. This negative perception could last for a significant period of time. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Foreign Securities Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Foreign Securities Risk. Investments in non-U.S. issuers may involve unique risks compared to investing in securities of U.S. issuers. These risks are more pronounced to the extent that the Fund invests a significant portion of its non-U.S. investments in one region or in the securities of emerging market issuers. See also " — Emerging Markets Risk" below. These risks may include: ● less information may be available about non-U.S. issuers or markets due to less rigorous disclosure or accounting standards or regulatory practices in foreign jurisdictions; ● many non-U.S. markets are smaller, less liquid and more volatile. In a changing market, Calamos may not be able to sell the Fund's portfolio securities at times, in amounts and at prices it considers reasonable; ● an adverse effect of currency exchange rate changes or controls on the value of the Fund's investments; ● the economies of non-U.S. countries may grow at slower rates than expected or may experience a downturn or recession; ● economic, political and social developments may adversely affect the securities markets in foreign jurisdictions, including expropriation and nationalization; ● the difficulty in obtaining or enforcing a court judgment in non-U.S. countries; ● restrictions on foreign investments in non-U.S. jurisdictions; ● difficulties in effecting the repatriation of capital invested in non-U.S. countries; ● withholding and other non-U.S. taxes may decrease the Fund's return; ● the ability for the Public Company Accounting Oversight Board, which regulates auditors of U.S. public companies, is unable to inspect audit work papers in certain foreign countries; ● often limited rights and few practical remedies to pursue shareholder claims, including class actions or fraud claims, and the ability of the Commission, the U.S. Department of Justice and other authorities to bring and enforce actions against foreign issuers or foreign persons is limited; and ● dividend income the Fund receives from foreign securities may not be eligible for the special tax treatment applicable to qualified dividend income. There may be less publicly available information about non-U.S. markets and issuers than is available with respect to U.S. securities and issuers. Non-U.S. companies generally are not subject to accounting, auditing and financial reporting standards, practices and requirements comparable to those applicable to U.S. companies. The trading markets for most non-U.S. securities are generally less liquid and subject to greater price volatility than the markets for comparable securities in the United States. The markets for securities in certain emerging markets are in the earliest stages of their development. Even the markets for relatively widely traded securities in certain non-U.S. markets, including emerging market countries, may not be able to absorb, without price disruptions, a significant increase in trading volume or trades of a size customarily undertaken by institutional investors in the United States. Additionally, market making and arbitrage activities are generally less extensive in such markets, which may contribute to increased volatility and reduced liquidity. Economies and social and political conditions in individual countries may differ unfavorably from those in the United States. Non-U.S. economies may have less favorable rates of growth of gross domestic product, rates of inflation, currency valuation, capital reinvestment, resource self-sufficiency and balance of payments positions. Many countries have experienced substantial, and in some cases extremely high, rates of inflation for many years. Inflation and rapid fluctuations in inflation rates have had, and may continue to have, very negative effects on the economies and securities markets of certain emerging market countries. Unanticipated political or social developments may also affect the values of the Fund's investments and the availability to the Fund of additional investments in such countries. Based upon the Fund's test for determining whether an issuer is a "foreign issuer" as described above, it is possible that an issuer of securities in which the Fund invests could be organized under the laws of a foreign country, yet still conduct a substantial portion of its business in the U.S. or have substantial assets in the U.S. In this case, such a "foreign issuer" may be subject to the market conditions in the U.S. to a greater extent than it may be subject to the market conditions in the country of its organization. See " — Non-U.S. Government Obligation Risk." |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Forward Currency Exchange Contracts Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Forward Currency Exchange Contracts Risk. Forward contracts are contractual agreements to purchase or sell a specified currency at a specified future date (or within a specified time period) at a price set at the time of the contract. The Fund may not fully benefit from, or may lose money on, forward foreign currency transactions if changes in currency exchange rates do not occur as anticipated or do not correspond accurately to changes in the value of the Fund's holdings. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Derivative Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | General Derivative Risks. Derivatives also involve the risk of mispricing or improper valuation and the risk that changes in the value of a derivative may not correlate perfectly with an underlying asset, interest rate or index. Suitable derivative transactions may not be available in all circumstances and there can be no assurance that the Fund will engage in these transactions to reduce exposure to other risks when that would be beneficial. Furthermore, the skills needed to employ derivatives strategies are different from those needed to select portfolio securities and, in connection with such strategies, the Fund makes predictions with respect to market conditions, liquidity, currency movements, market values, interest rates and other applicable factors, which may be inaccurate. Thus, the use of derivative investments may require the Fund to sell or purchase portfolio securities at inopportune times or for prices below or above the current market values, may limit the amount of appreciation the Fund can realize on an investment or may cause the Fund to hold a security that it might otherwise want to sell. Tax rules governing the Fund's transactions in derivative instruments may also affect whether gains and losses recognized by the Fund are treated as ordinary or capital, accelerate the recognition of income or gains to the Fund, defer losses to the Fund, and cause adjustments in the holding periods of the Fund's securities, thereby affecting, among other things, whether capital gains and losses are treated as short-term or long-term. These rules could therefore affect the amount, timing and/or character of distributions to shareholders. In addition, there may be situations in which the Fund elects not to use derivative instruments that result in losses greater than if they had been used. Amounts paid by the Fund as premiums and cash or other assets held in margin accounts with respect to the Fund's derivative instruments would not be available to the Fund for other investment purposes, which may result in lost opportunities for gain. Derivative instruments can be illiquid, and may disproportionately increase losses and may have a potentially large impact on Fund performance. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Geographic Concentration Risks [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Geographic Concentration Risk. Investments in a particular country or geographic region may be particularly susceptible to political, diplomatic or economic conditions and regulatory requirements. To the extent the Fund concentrates its investments in a particular country, region or group of regions, the Fund may be more volatile than a more geographically diversified fund. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
High Yield Securities Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | High Yield Securities Risk. The Fund may invest in high yield securities of any rating. Investment in high yield securities involves substantial risk of loss. Below investment grade non-convertible debt securities or comparable unrated securities are commonly referred to as "junk bonds" and are considered predominantly speculative with respect to the issuer's ability to pay interest and principal and are susceptible to default or decline in market value due to adverse economic and business developments. The market values for high yield securities tend to be very volatile, and these securities are less liquid than investment grade debt securities. For these reasons, your investment in the Fund is subject to the following specific risks: ● increased price sensitivity to changing interest rates and to a deteriorating economic environment; ● greater risk of loss due to default or declining credit quality; ● adverse company specific events are more likely to render the issuer unable to make interest and/or principal payments; and ● if a negative perception of the high yield market develops, the price and liquidity of high yield securities may be depressed. This negative perception could last for a significant period of time. Securities rated below investment grade are speculative with respect to the capacity of the issuer to pay interest and repay principal in accordance with the terms of such securities. A rating of "Ba1" from Moody's means that the issue so rated can have speculative elements and is subject to substantial credit risk. Standard & Poor's assigns a rating of "BB+" to issues that are less vulnerable to nonpayment than other speculative issues, but nonetheless subject to major ongoing uncertainties or exposure to adverse business, financial, or economic conditions which could lead to the obligor's inadequate capacity to meet its financial commitment on the obligation. A rating of "C" from Moody's means that the issue so rated can be regarded as having extremely poor prospects of ever attaining any real investment standing. Standard & Poor's assigns a rating of "C" to issues that are currently highly vulnerable to nonpayment, and the "C" rating may be used to cover a situation in which a bankruptcy petition has been filed or similar action taken, but payments on the obligation are being continued (a "C" rating is also assigned to a preferred stock issue in arrears on dividends or sinking fund payments, but that is currently paying). See the statement of additional information for a description of Moody's and Standard & Poor's ratings. Adverse changes in economic conditions are more likely to lead to a weakened capacity of a high yield issuer to make principal payments and interest payments than an investment grade issuer. The principal amount of high yield securities outstanding has proliferated in the past decade as an increasing number of issuers have used high yield securities for corporate financing. An economic downturn could severely affect the ability of highly leveraged issuers to service their debt obligations or to repay their obligations upon maturity. Similarly, downturns in profitability in specific industries could adversely affect the ability of high yield issuers in those industries to meet their obligations. The market values of lower quality debt securities tend to reflect individual developments of the issuer to a greater extent than do higher quality securities. Factors having an adverse impact on the market value of lower quality securities may have an adverse effect on the Fund's net asset value and the market value of its common shares. In addition, the Fund may incur additional expenses to the extent it is required to seek recovery upon a default in payment of principal or interest on its portfolio holdings. In certain circumstances, the Fund may be required to foreclose on an issuer's assets and take possession of its property or operations. In such circumstances, the Fund would incur additional costs in disposing of such assets and potential liabilities from operating any business acquired. The secondary market for high yield securities may not be as liquid as the secondary market for more highly rated securities, a factor which may have an adverse effect on the Fund's ability to dispose of a particular security. There are fewer dealers in the market for high yield securities than for investment grade obligations. The prices quoted by different dealers may vary significantly and the spread between the bid and asked price is generally much larger than for higher quality instruments. Under adverse market or economic conditions, the secondary market for high yield securities could contract further, independent of any specific adverse changes in the condition of a particular issuer, and these instruments may become illiquid. As a result, the Fund could find it more difficult to sell these securities or may be able to sell the securities only at prices lower than if such securities were widely traded. Prices realized upon the sale of such lower rated or unrated securities, under these circumstances, may be less than the prices used in calculating the Fund's NAV. Because investors generally perceive that there are greater risks associated with lower quality debt securities of the type in which the Fund may invest a portion of its assets, the yields and prices of such securities may tend to fluctuate more than those for higher rated securities. In the lower quality segments of the debt securities market, changes in perceptions of issuers' creditworthiness tend to occur more frequently and in a more pronounced manner than do changes in higher quality segments of the debt securities market, resulting in greater yield and price volatility. If the Fund invests in high yield securities that are rated "C" or below, the Fund will incur significant risk in addition to the risks associated with investments in high yield securities and corporate loans. Distressed securities frequently do not produce income while they are outstanding. The Fund may purchase distressed securities that are in default or the issuers of which are in bankruptcy. The Fund may be required to bear certain extraordinary expenses in order to protect and recover its investment. The Fund also will be subject to significant uncertainty as to when and in what manner and for what value the obligations evidenced by the distressed securities will eventually be satisfied. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Inflation Risks [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Inflation Risk. Inflation is the reduction in the purchasing power of money resulting from an increase in the price of goods and services. Inflation risk is the risk that the inflation adjusted or "real" value of an investment in preferred stock or debt securities or the income from that investment will be worth less in the future. As inflation occurs, the real value of the preferred stock or debt securities and the dividend payable to holders of preferred stock or interest payable to holders of debt securities declines. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest Rate Risks [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Interest Rate Risk. In addition to the risks described above, debt securities, including high yield securities, are subject to certain risks, including: ● if interest rates go up, the value of debt securities in the Fund's portfolio generally will decline; ● during periods of declining interest rates, the issuer of a security may exercise its option to prepay principal earlier than scheduled, forcing the Fund to reinvest in lower yielding securities. This is known as call or prepayment risk. Debt securities frequently have call features that allow the issuer to repurchase the security prior to its stated maturity. An issuer may redeem an obligation if the issuer can refinance the debt at a lower cost due to declining interest rates or an improvement in the credit standing of the issuer; ● during periods of rising interest rates, the average life of certain types of securities may be extended because of slower than expected principal payments. This may lock in a below market interest rate, increase the estimated period until the security is paid in full and reduce the value of the security. This is known as extension risk; ● rising interest rates could result in an increase in the cost of the Fund's leverage and could adversely affect the ability of the Fund to meet asset coverage requirements with respect to leverage; and ● variable rate securities generally are less sensitive to interest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as interest rates in general. When the Fund holds variable rate securities, a decrease in market interest rates will adversely affect the income received from such securities and the NAV of the Fund's shares. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Benchmark Rate Risk And Libor Cessation [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Benchmark Rate Risk and LIBOR Cessation. The London Interbank Offered Rate (“LIBOR”) was the offered rate for short-term Eurodollar deposits between major international banks. The terms of investments, financings or other transactions (including certain derivatives transactions) to which the Fund may be a party have historically been tied to LIBOR. In connection with the global transition away from LIBOR led by regulators and market participants, LIBOR was last published on a representative basis at the end of June 2023. Alternative reference rates to LIBOR have been established in most major currencies and the transition to new reference rates continues. Markets in these new rates are developing, but questions around liquidity and how to appropriately mitigate any economic value transfer as a result of the transition remain a concern. The transition away from LIBOR and the use of replacement rates may adversely affect transactions that used LIBOR as a reference rate, financial institutions, funds and other market participants that engaged in such transactions, and the financial markets generally. The impact of the transition away from LIBOR on the Fund or the financial instruments in which the Fund invests cannot yet be fully determined. In addition, interest rates or other types of rates and indices which are classed as “benchmarks” have been the subject of ongoing national and international regulatory reform, including under the European Union regulation on indices used as benchmarks in financial instruments and financial contracts (known as the “Benchmarks Regulation”). The Benchmarks Regulation has been enacted into United Kingdom law by virtue of the European Union (Withdrawal) Act 2018 (as amended), subject to amendments made by the Benchmarks (Amendment and Transitional Provision) (EU Exit) Regulations 2019 (SI 2019/657) and other statutory instruments. Following the implementation of these reforms, the manner of administration of benchmarks has changed and may further change in the future, with the result that relevant benchmarks may perform differently than in the past, the use of benchmarks that are not compliant with the new standards by certain supervised entities may be restricted, and certain benchmarks may be eliminated entirely. Additionally, there could be other consequences which cannot be predicted. As a result of the transition away from LIBOR as a benchmark reference for interest rates, certain bonds and loans held by the Fund may have floating interest rates based on SOFR or, if otherwise provided in the underlying contracts, other alternative benchmark rates. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
SOFR Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | SOFR Risk. SOFR is a relatively new index rate calculated based on short-term repurchase agreements backed by U.S. Treasury Instruments. While LIBOR is an unsecured rate, SOFR is a secured rate. SOFR, unlike LIBOR, reflects actual market transactions. Accordingly, SOFR is not the economic equivalent of LIBOR. Consequently, there can be no assurance that SOFR will perform in the same way as LIBOR would have at any time, including, without limitation, as a result of changes in interest and yield rates in the market, monetary policy, bank credit risk, market volatility or global or regional economic, financial, political, regulatory, judicial or other events. Because SOFR is published by the Federal Reserve Bank of New York (the “New York Fed”) based on data received from other sources, the Adviser will have no control over its determination, calculation, or publication. There can be no assurance that SOFR will not be discontinued or fundamentally altered in a manner that is materially adverse to the interests of the Fund. If the manner in which SOFR is calculated is changed, that change may result in a reduction of the amount of interest payable on SOFR-linked floating rate instruments and the trading prices of such instruments. Additionally, daily changes in SOFR have, on occasion, been more volatile than daily changes in other benchmark or market rates. Although occasional, increased daily volatility in SOFR would not necessarily lead to more volatile interest payments, the return on and value of SOFR-linked floating rate instruments may fluctuate more than floating rate instruments that are linked to less volatile rates. All of the foregoing risks may affect the performance of the applicable bonds and loans in which the Fund invests, which in turn may adversely affect the performance of the Fund. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Alternative Benchmark Rate Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Alternative Benchmark Rate Risk. As stated above, some of the bonds and loans held by the Fund may have floating interest rates based on alternative benchmark rates other than SOFR. Such alternative benchmark rates, like SOFR, may not have been widely used by market participants until relatively recently, and they may not perform exactly the same as LIBOR because they are calculated and administered differently. Generally, the use of alternative benchmark rates (including SOFR) may (i) cause the value of the interest rate on such bonds and loans to be uncertain or to be lower or more volatile than it would otherwise be, (ii) result in uncertainty as to the functioning, liquidity or value of such bonds and loans, and/or (iii) involve actions of regulators or rate administrators that may adversely affect certain markets or contracts underlying such bonds and loans. All of the foregoing could adversely affect the return on and value of the related floating rate instruments in which the Fund invests. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Leverage Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Leverage Risk. The derivative instruments in which the Fund may invest will give rise to forms of financial leverage, which may magnify the risk of owning such instruments. Derivatives generally involve leverage in the sense that the investment exposure created by the derivatives may be significantly greater than the Fund’s initial investment in the derivative. Accordingly, if the Fund enters into a derivative transaction, it could lose substantially more than the principal amount invested. Additionally, as a closed-end investment company registered with the SEC, the Fund is subject to the federal securities laws, including the 1940 Act, the rules thereunder, and various SEC and SEC staff interpretive positions. In accordance with these laws, rules and positions, the Fund may “set aside” liquid assets (often referred to as “asset segregation”), or engage in other SEC or staff-approved measures, to “cover” open positions with respect to certain portfolio management techniques, such as engaging in reverse repurchase agreements, dollar rolls, entering into credit default swaps or futures contracts, or purchasing securities on a when-issued or delayed delivery basis, that may be considered senior securities under the 1940 Act. The Fund intends to cover its derivative positions by maintaining an amount of cash or liquid securities in a segregated account equal to the face value of those positions and by offsetting derivative positions against one another or against other assets to manage the effective market exposure resulting from derivatives in its portfolio. To the extent that the Fund does not segregate liquid assets or otherwise cover its obligations under such transactions, such transactions will be treated as senior securities representing indebtedness for purposes of the requirement under the 1940 Act that the Fund may not enter into any such transactions if the Fund’s borrowings would thereby exceed 33 1/3% of its managed assets, less all liabilities and indebtedness of the Fund not represented by senior securities. However, these transactions, even if covered, may represent a form of economic leverage and will create risks. In addition, these segregation and coverage requirements could result in the Fund maintaining securities positions that it would otherwise liquidate, segregating assets at a time when it might be disadvantageous to do so or otherwise restricting portfolio management. Such segregation and cover requirements will not limit or offset losses on related positions. The Fund has issued indebtedness and preferred shares and may borrow money or issue debt securities as permitted by the 1940 Act. As of January 31, 2025, the Fund has leverage in the form of borrowings under the SSB Agreement and outstanding MRP Shares. Leverage is the potential for the Fund to participate in gains and losses on an amount that exceeds the Fund's investment. The borrowing of money or issuance of debt securities and preferred shares represents the leveraging of the Fund's common shares. As a non-fundamental policy, the Fund may not issue preferred shares or borrow money and/or issue debt securities with an aggregate liquidation preference and aggregate principal amount exceeding 38% of the Fund's managed assets as measured at the time of borrowing or issuance of the new securities. However, the Board of Trustees reserves the right to issue preferred shares or debt securities or borrow to the extent permitted by the 1940 Act and the Fund's policies. See "Leverage." Leverage creates risks which may adversely affect the return for the holders of common shares, including: ● the likelihood of greater volatility in the NAV and market price of the Fund's common shares; ● fluctuations in the dividend rates on any preferred shares borne by the Fund or in interest rates on borrowings and short-term debt; ● increased operating costs, which are effectively borne by common shareholders, may reduce the Fund's total return; and ● the potential for a decline in the value of an investment acquired with borrowed funds, while the Fund's obligations under such borrowing or preferred shares remain fixed. In addition, the rights of lenders and the holders of preferred shares and debt securities issued by the Fund will be senior to the rights of the holders of common shares with respect to the payment of dividends or to the payment of assets upon liquidation. Holders of preferred shares have voting rights in addition to and separate from the voting rights of common shareholders. See "Description of Securities — Preferred Shares" and "Certain Provisions of the Agreement and Declaration of Trust and By-Laws, Including Antitakeover Provisions." The holders of preferred shares or debt, if any, on the one hand, and the holders of the common shares, on the other, may have interests that conflict in certain situations. The Fund's use of leverage is premised upon the expectation that the Fund's preferred share dividends or borrowing cost will be lower than the return the Fund achieves on its investments with the proceeds of the issuance of preferred shares or debt securities or borrowing. Such difference in return may result from the Fund's higher credit rating or the short-term nature of its borrowing compared to the lower credit quality, long-term nature of its investments. Because Calamos seeks to invest the Fund's managed assets (including the assets obtained from leverage) in a portfolio of potentially higher yielding investments or portfolio investments with the potential for capital appreciation, the holders of common shares will be the beneficiaries of any incremental return but will bear the risk of loss on investments made with the leverage proceeds. Should the differential between the Fund's return on its investments made with the proceeds of leverage and the cost of the leverage narrow, the incremental return "pick up" will be reduced or the Fund may incur losses. If long-term interest rates rise without a corresponding increase in the yield on the Fund's portfolio investments or the Fund otherwise incurs losses on its investments, the Fund's net asset value attributable to its common shareholders will reflect the decline in the value of portfolio holdings resulting therefrom. Leverage is a speculative technique that could adversely affect the returns to common shareholders. Leverage can cause the Fund to lose money and can magnify the effect of any losses. To the extent the income or capital appreciation derived from securities purchased with funds received from leverage exceeds the cost of leverage, the Fund's return will be greater than if leverage had not been used. Conversely, if the income or capital appreciation from the securities purchased with such funds is not sufficient to cover the cost of leverage or if the Fund incurs capital losses, the return of the Fund will be less than if leverage had not been used, and therefore the amount available for distribution to common shareholders as dividends and other distributions will be reduced or potentially eliminated. The Fund will pay, and common shareholders will effectively bear, any costs and expenses relating to any borrowings and to the issuance and ongoing maintenance of preferred shares or debt securities. Such costs and expenses include the higher management fee resulting from the use of any such leverage, offering and/or issuance costs, and interest and/or dividend expense and ongoing maintenance. These conditions may, directly or indirectly, result in higher leverage costs to common shareholders. Certain types of borrowings may result in the Fund being subject to covenants in credit agreements, including those relating to asset coverage, borrowing base and portfolio composition requirements and additional covenants that may affect the Fund's ability to pay dividends and distributions on common shares in certain instances. The Fund may also be required to pledge its assets to the lenders in connection with certain types of borrowings. The Fund may be subject to certain restrictions on investments imposed by guidelines of and covenants with rating agencies which may issue ratings for the preferred shares or short-term debt instruments issued by the Fund. These guidelines and covenants may impose asset coverage or portfolio composition requirements that are more stringent than those imposed by the 1940 Act. If the Fund's ability to make dividends and distributions on its common shares is limited, such limitation could, under certain circumstances, impair the ability of the Fund to maintain its qualification for taxation as a regulated investment company or to reduce or eliminate tax at the Fund level, which would have adverse tax consequences for common shareholders. To the extent that the Fund is required, in connection with maintaining 1940 Act asset coverage requirements or otherwise, or elects to redeem any preferred shares or debt securities or prepay any borrowings, the Fund may need to liquidate investments to fund such redemptions or prepayments. Liquidation at times of adverse economic conditions may result in capital loss and reduce returns to common shareholders. The Board reserves the right to change the amount and type of leverage that the Fund uses, and reserves the right to implement changes to the Fund's borrowings that it believes are in the long-term interests of the Fund and its shareholders, even if such changes impose a higher interest rate or other costs or impacts over the intermediate, or short-term time period. There is no guarantee that the Fund will maintain leverage at the current rate, and the Board reserves the right to raise, decrease, or eliminate the Fund's leverage exposure. See "Prospectus Summary — Use of Leverage by the Fund." Because Calamos' investment management fee is a percentage of the Fund's managed assets, Calamos' fee will be higher if the Fund is leveraged and Calamos will have an incentive to be more aggressive and leverage the Fund. Consequently, the Fund and Calamos may have differing interests in determining whether to leverage the Fund's assets. Any additional use of leverage by the Fund effected through new, additional or increased credit facilities or the issuance of preferred shares would require approval by the Board. In considering whether to approve the use of additional leverage, the Board would be presented with all relevant information necessary to make a determination whether or not additional leverage through those means would be in the best interests of the Fund, including information regarding any potential conflicts of interest. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Liquidity Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Liquidity Risk. The Fund may invest without limit in securities that, at the time of investment, are illiquid (i.e., any investment that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment). The Fund may also invest without limit in Rule 144A Securities determined to be liquid. Calamos, under the supervision and oversight of the Board of Trustees, will determine whether Rule 144A Securities are illiquid (that is, not readily marketable). Illiquid securities may be difficult to dispose of at a fair price at the times when the Fund believes it is desirable to do so. Investment of the Fund's assets in illiquid securities may restrict the Fund's ability to take advantage of market opportunities. The market price of illiquid securities generally is more volatile than that of more liquid securities, which may adversely affect the price that the Fund pays for or recovers upon the sale of illiquid securities. Illiquid securities are also more difficult to value and may be fair valued in which case Calamos' judgment may play a greater role in the valuation process. The risks associated with illiquid securities may be particularly acute in situations in which the Fund's operations require cash and could result in the Fund borrowing to meet its short-term needs or incurring losses on the sale of illiquid securities. The Fund may also invest without limitation in securities that have not been registered for public sale, but that are eligible for purchase and sale by certain qualified institutional buyers. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Loan Risk. The Fund may invest in loans which may not be (i) rated at the time of investment, (ii) registered with the SEC or (iii) listed on a securities exchange. There may not be as much public information available regarding these loans as is available for other Fund investments, such as exchange-listed securities. As well, there may not be an active trading market for some loans, meaning they may be illiquid and more difficult to value than other more liquid securities. Settlement periods for loans are longer than for exchange-traded securities, typically ranging between 1 and 3 weeks, and in some cases much longer. There is no central clearinghouse for loan trades, and the loan market has not established enforceable settlement standards or remedies for failure to settle. Because the interest rates of floating-rate loans in which the Fund may invest may reset frequently, if market interest rates fall, the loans' interest rates will be reset to lower levels, potentially reducing the Fund's income. Because the adviser may wish to invest in the publicly-traded securities of an obligor, the Fund may not have access to material non-public information regarding the obligor to which other investors have access. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Management Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Management Risk. Calamos' judgment about the attractiveness, relative value or potential appreciation of a particular sector, security or investment strategy may prove to be incorrect. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Market Disruption Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Market Disruption Risk. Certain events have a disruptive effect on the securities markets, such as terrorist attacks, war and other geopolitical events, earthquakes, storms and other disasters. The Fund cannot predict the effects of similar events in the future on the U.S. economy or any foreign economy. High yield securities tend to be more volatile than higher rated debt securities so that these events and any actions resulting from them may have a greater impact on the prices and volatility of high yield securities than on higher rated securities. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Master Limited Partnerships Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Master Limited Partnerships Risk. Investments in MLPs involve risks that differ from investments in common stock. Holders of MLP common units are subject to certain risks inherent in the structure of MLPs, including (i) tax risks, (ii) risk related to limited control of management or the general partner or managing member, (iii) limited rights to vote on matters affecting the MLP, except with respect to extraordinary transactions, (iv) conflicts of interest between the general partner or managing member and its affiliates, on the one hand, and the limited partners or members, on the other hand, including those arising from incentive distribution payments or corporate opportunities, and (v) cash flow risks. MLP common units and other equity securities can be affected by macro-economic and other factors affecting the stock market in general, expectations of interest rates, investor sentiment towards MLPs or the energy sector, changes in a particular issuer's financial condition, or unfavorable or unanticipated poor performance of a particular issuer (in the case of MLPs, generally measured in terms of distributable cash flow). Prices of common units of individual MLPs and other equity securities also can be affected by fundamentals unique to the partnership or company, including cash flow growth, cash generating power and distribution coverage. Although certain MLPs may trade on national securities exchanges, certain MLPs may trade less frequently than those of larger companies due to their market capitalizations. Due to limited trading volumes of certain MLPs, the prices of such MLPs may display abrupt or erratic movements at times. Additionally, it may be more difficult for the Fund to buy and sell significant amounts of such securities without an unfavorable impact on prevailing market prices. The Fund's investment in securities that are less actively traded or over time experience decreased trading volume may restrict its ability to dispose of the securities at a fair price. Such a situation may prevent the Fund from limiting losses or realizing gains. This also may adversely affect the Fund's ability to make dividend distributions to shareholders. MLPs are generally treated as partnerships for U.S. federal income tax purposes. Partnerships do not pay U.S. federal income tax at the partnership level. Rather, each partner is allocated a share of the partnership's income, gains, losses, deductions and expenses. A change in current tax law, or a change in the business of a given MLP, could result in an MLP being treated as a corporation for U.S. federal income tax purposes. As a result, the amount of cash available for distribution by the MLP would be reduced and the after-tax return to the Fund with respect to its investment in such MLPs would be materially reduced. Thus, if any of the MLPs owned by the Fund were treated as corporations for U.S. federal income tax purposes, it could result in a reduction in the value of the Fund. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Maturity Risk. Interest rate risk will generally affect the price of a fixed income security more if the security has a longer maturity. Fixed income securities with longer maturities will therefore be more volatile than other fixed income securities with shorter maturities. Conversely, fixed income securities with shorter maturities will be less volatile but generally provide lower potential returns than fixed income securities with longer maturities. The average maturity of the Fund's investments may affect the volatility of the Fund's share price. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Non-Convertible Income Securities Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Non-Convertible Income Securities Risk. The Fund will also invest in non-convertible income securities. The Fund's investments in non-convertible income securities may have fixed or variable principal payments and all types of interest rate and dividend payment and reset terms, including fixed rate, adjustable rate, zero coupon, contingent, deferred, payment in kind and auction rate features. Recent events in the fixed-income markets, including the potential impact of the Federal Reserve Board tapering its quantitative easing program, may expose the Fund to heightened interest rate risk and volatility. In addition, the Fund is subject to the risk that interest rates may exhibit increased volatility, which could cause the Fund's net asset value to fluctuate more. A decrease in fixed-income market maker capacity may act to decrease liquidity in the fixed-income markets and act to further increase volatility, affecting the Fund's return. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Non-US Government Obligation Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Non-U.S. Government Obligation Risk. An investment in debt obligations of non-U.S. governments and their political subdivisions involves special risks that are not present in corporate debt obligations. The non-U.S. issuer of the sovereign debt or the non-U.S. governmental authorities that control the repayment of the debt may be unable or unwilling to repay principal or interest when due, and the Fund may have limited recourse in the event of a default. During periods of economic uncertainty, the market prices of sovereign debt may be more volatile than prices of debt obligations of U.S. issuers. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Portfolio Selection Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Portfolio Selection Risk. The value of your investment may decrease if the investment adviser's judgment about the attractiveness, value or market trends affecting a particular security, issuer, industry or sector or about market movements is incorrect. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Portfolio Turnover Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Portfolio Turnover Risk. The portfolio managers may actively and frequently trade securities or other instruments in the Fund's portfolio to carry out its investment strategies. A high portfolio turnover rate increases transaction costs, which may increase the Fund's expenses. Frequent and active trading may also cause adverse tax consequences for investors in the Fund due to an increase in short-term capital gains. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Recent Market Events Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Recent Market Events. Since the 2008 financial crisis, financial markets throughout the world have experienced increased periods of volatility, depressed valuations, decreased liquidity and heightened uncertainty and turmoil. This turmoil resulted in unusual and extreme volatility in the equity and debt markets, in the prices of individual securities and in the world economy. Events that have contributed to these market conditions include, but are not limited to, major cybersecurity events, geopolitical events (such as wars (including Russia’s military invasion of Ukraine), terror attacks, natural or environmental disasters, country instability, and public health emergencies), measures to address budget deficits, downgrading of sovereign debt, dramatic changes in currency exchange rates, and public sentiment. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time. Widespread disease and virus epidemics and pandemics, such as the coronavirus outbreak, could likewise be highly disruptive, adversely affecting individual companies, sectors, industries, markets, currencies, interest and inflation rates, credit ratings, investor sentiment, and other factors affecting the value of the Fund's investments. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Regulatory Risk. Derivatives markets are subject to various risks related to existing as well as new and evolving regulations both within and outside the United States. For example, in the United States, new or amended regulations may be imposed by the U.S. Commodity Futures Trading Commission (the “CFTC”), the SEC, the Federal Reserve or other financial regulators, other governmental regulatory authorities or self-regulatory organizations that supervise the financial markets that could adversely affect the Fund. In particular, these agencies are empowered to promulgate a variety of new rules pursuant to financial reform legislation in the United States. The Fund also may be adversely affected by changes in the enforcement or interpretation of existing statues and rules by these governmental regulatory authorities or self-regulatory organizations. In addition, the securities and futures markets are subject to comprehensive statutes, regulations and margin requirements. For instance, the Dodd — Frank Wall Street Reform and Consumer Protection Act of 2010 ("Dodd-Frank Act") could have an adverse effect on the Fund's ability to use derivative instruments. The Dodd-Frank Act is designed to impose stringent regulation on the over-the-counter derivatives market in an attempt to increase transparency and accountability and provides for, among other things, clearing, execution, margin, reporting, recordkeeping, business conduct, disclosure, position limit, minimum net capital and registration requirements. Because regulations that are being implemented by these requirements are evolving (and some of the regulations are not yet final), their ultimate impact remains unclear. Similar requirements are in the process of being implemented in the European Union, the United Kingdom and other jurisdictions which may impact the Fund’s transactions with entities domiciled in such jurisdictions and subject to such requirements. These regulations could, among other things, restrict the Fund's ability to engage in derivatives transactions (for example, by making certain types of derivatives transactions no longer available to our funds), increase the costs of using these instruments (for example, by increasing margin, capital or reporting requirements) and/or make them less effective and, as a result, the Fund may be unable to execute its investment strategy. Limits or restrictions applicable to the counterparties with which the Fund engages in derivative transactions could also prevent the Fund from using these instruments, affect the pricing or other factors relating to these instruments or may change availability of certain investments. It is unclear how the regulatory changes will affect counterparty risk. Rule 18f-4 under the 1940 Act provides for the regulation of registered investment companies' use of derivatives and certain related instruments. The rule, among other things, limits derivatives exposure through one of two value-at-risk tests, requires funds to adopt and implement a derivatives risk management program (including the appointment of a derivatives risk manager and the implementation of certain testing requirements), and subjects funds to certain reporting requirements in respect of derivatives. Limited derivatives users (as determined by Rule 18f-4) are not, however, subject to the full requirements under the rule. Rule 18f-4 could restrict the Fund's ability to engage in certain derivatives transactions and/or increase the costs of such derivatives transactions, which could adversely affect the value or performance of the Fund. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
REIT Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | REIT Risk. Investing in real estate investment trusts (“REITs”) involves certain unique risks in addition to those risks associated with investing in the real estate industry in general. An equity REIT may be affected by changes in the value of the underlying properties owned by the REIT. A mortgage REIT may be affected by changes in interest rates and the ability of the issuers of its portfolio mortgages to repay their obligations. REITs are dependent upon the skills of their managers and are not diversified. REITs are generally dependent upon maintaining cash flows to repay borrowings and to make distributions to shareholders and are subject to the risk of default by lessees or borrowers. REITs whose underlying assets are concentrated in properties used by a particular industry, such as health care, are also subject to risks associated with such industry. REITs (especially mortgage REITs) are also subject to interest rate risks. When interest rates decline, the value of a REIT's investment in fixed rate obligations can be expected to rise. Conversely, when interest rates rise, the value of a REIT's investment in fixed rate obligations can be expected to decline. If the REIT invests in adjustable rate mortgage loans the interest rates on which are reset periodically, yields on a REIT's investments in such loans will gradually align themselves to reflect changes in market interest rates. This causes the value of such investments to fluctuate less dramatically in response to interest rate fluctuations than would investments in fixed rate obligations. REITs may have limited financial resources, may utilize significant amounts of leverage, may trade less frequently and in a limited volume and may be subject to more abrupt or erratic price movements than larger company securities. Historically, REITs have been more volatile in price than the larger capitalization stocks included in Standard & Poor's 500 Stock Index. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risks Associated With Options [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Risks Associated with Options. The Fund may use options, including on the Fund's convertible securities or during the creation of synthetic convertible instruments. There are several risks associated with transactions in options. For example, there are significant differences between the securities markets and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. A decision as to whether, when and how to use options involves the exercise of skill and judgment, and even a well-conceived transaction may be unsuccessful to some degree because of market behavior or unexpected events. The Fund's ability to utilize options successfully will depend on Calamos' ability to predict pertinent market movements, which cannot be assured. The Fund intends to seek to generate income from option premiums by writing (selling) options. The Fund may write (sell) call options (i) on a portion of the equity securities (including securities that are convertible into equity securities) in the Fund's portfolio, (ii) on a portion of the equity securities the Fund has a right to receive upon conversion of a convertible security that it owns at the time it writes the call, and (iii) on broad-based securities indices (such as the S&P 500 or MSCI EAFE) or certain ETFs that trade like common stocks but seek to replicable such market indices. All call options sold by the Fund must be "covered." For example, a call option written by the Fund will require the Fund to hold the securities subject to the call (or securities convertible into the needed securities without additional consideration) or to segregate cash or liquid assets sufficient to purchase and deliver the securities if the call is exercised. Even though the Fund will receive the option premium to help protect it against loss, a call option sold by the Fund exposes the Fund during the term of the option to possible loss of opportunity to realize appreciation in the market price of the underlying security or instrument and may require the Fund to hold a security or instrument that it might otherwise have sold. The Fund may purchase and sell put options on individual securities and securities indices. In selling put options, there is a risk that the Fund may be required to buy the underlying security at a disadvantageous price above the market price. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rule 144A Securities Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Rule 144A Securities Risk. The Fund may invest in securities that are issued and sold through transactions under Rule 144A of the Securities Act of 1933. Under the supervision and oversight of the Board of Trustees, Calamos will determine whether Rule 144A Securities are illiquid. If qualified institutional buyers are unwilling to purchase these Rule 144A Securities, the percentage of the Fund's assets invested in illiquid securities would increase. Typically, the Fund purchases Rule 144A Securities only if the Fund's adviser has determined them to be liquid. If any Rule 144A Security held by the Fund should become illiquid, the value of the security may be reduced and a sale of the security may be more difficult. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sector Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Sector Risk. To the extent the Fund invests a significant portion of its assets in a particular sector, a greater portion of the Fund's performance may be affected by the general business and economic conditions affecting that sector. Each sector may share economic risk with the broader market, however there may be economic risks specific to each sector. As a result, returns from those sectors may trail returns from the overall stock market and it is possible that the Fund may underperform the broader market, or experience greater volatility. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Synthetic Convertible Instruments Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Synthetic Convertible Instruments Risk. The value of a synthetic convertible instrument may respond differently to market fluctuations than a convertible instrument because a synthetic convertible instrument is composed of two or more separate securities, each with its own market value. In addition, if the value of the underlying common stock or the level of the index involved in the convertible component falls below the exercise price of the warrant or option, the warrant or option may lose all value. Synthetic convertible instruments created by other parties have the same attributes of a convertible security; however, the issuer of the synthetic convertible instrument assumes the credit risk associated with the investment, rather than the issuer of the underlying equity security into which the instrument is convertible. Investing in synthetic convertible instruments also involves the risk that the Fund does not achieve the investment exposure desired by Calamos. The Fund remains subject to the credit risk associated with the counterparty creating the synthetic convertible instrument. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Tax Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Tax Risk. The Fund may invest in certain securities, such as certain convertible securities and high yield securities, for which the federal income tax treatment may not be clear or may be subject to recharacterization by the IRS. It could be more difficult for the Fund to comply with certain federal income tax requirements applicable to regulated investment companies if the tax characterization of the Fund's investments is not clear or if the tax treatment of the income from such investments was successfully challenged by the IRS. Any failure to comply with the rules applicable to regulated investment companies could cause the Fund to fail to qualify as such. In addition, the tax treatment of the Fund may be affected by future interpretations of the Code and changes in the tax laws and regulations, all of which may apply with retroactive effect. See "Certain Federal Income Tax Matters." Certain of the Fund's investment practices may be subject to special and complex federal income tax provisions that may, among other things, (i) disallow, suspend or otherwise limit the allowance of certain losses or deductions, (ii) convert tax-advantaged, long-term capital gains and qualified dividend income into higher taxed short-term capital gain or ordinary income, (iii) increase ordinary income distributions, (iv) convert an ordinary loss or a deduction into a capital loss (the deductibility of which is more limited), (v) cause the Fund to recognize income or gain without a corresponding receipt of cash, (vi) adversely affect the timing as to when a purchase or sale of stock or securities is deemed to occur, and (vii) adversely alter the characterization of certain complex financial transactions. The Fund will monitor its transactions and may make certain tax elections where applicable in order to mitigate the effect of these provisions, if possible. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
US Government Security Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | U.S. Government Security Risk. Some securities issued by U.S. Government agencies or government sponsored enterprises are not backed by the full faith and credit of the U.S. and may only be supported by the right of the agency or enterprise to borrow from the U.S. Treasury. There can be no assurance that the U.S. Government will always provide financial support to those agencies or enterprises. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Volatility Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Volatility Risk. Risk may arise in connection with the use of derivative instruments from volatility of interest rates and the prices of reference instruments. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Diminished Voting Power And Excess Cash Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Diminished Voting Power and Excess Cash Risk. The voting power of current shareholders will be diluted to the extent that such shareholders do not purchase shares in any future common share offerings or do not purchase sufficient shares to maintain their percentage interest. In addition, if the Fund is unable to invest the proceeds of such offering as intended, its per share distribution may decrease (or may consist of return of capital) and the Fund may not participate in market advances to the same extent as if such proceeds were fully invested as planned. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest Rate Transactions Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Interest Rate Transactions Risk. The Fund may enter into an interest rate swap, cap or floor transaction to attempt to protect itself from increasing dividend or interest expenses on its leverage resulting from increasing short-term interest rates and to hedge its portfolio securities. A decline in interest rates may result in a decline in the value of the swap or cap, which may result in a decline in the net asset value of the Fund. Depending on the state of interest rates in general, the Fund's use of interest rate swap or cap transactions could enhance or harm the overall performance of the common shares. To the extent there is a decline in interest rates, the value of the interest rate swap or cap could decline, and could result in a decline in the net asset value of the common shares. In addition, if the counterparty to an interest rate swap or cap defaults, the Fund would not be able to use the anticipated net receipts under the swap or cap to offset the dividend or interest payments on the Fund's leverage or offset certain losses in its portfolio. Depending on whether the Fund would be entitled to receive net payments from the counterparty on the swap or cap, which in turn would depend on the general state of short-term interest rates at that point in time, such a default could negatively impact the performance of the common shares. In addition, at the time an interest rate swap or cap transaction reaches its scheduled termination date, there is a risk that the Fund would not be able to obtain a replacement transaction or that the terms of the replacement would not be as favorable as on the expiring transaction. If either of these events occurs, it could have a negative impact on the performance of the common shares. If the Fund fails to maintain a required 200% asset coverage of the liquidation value of any outstanding preferred shares or if the Fund loses its rating on its preferred shares or fails to maintain other covenants with respect to the preferred shares, the Fund may be required to redeem some or all of the preferred shares. Similarly, the Fund could be required to prepay the principal amount of any debt securities or other borrowings. Such redemption or prepayment would likely result in the Fund seeking to terminate early all or a portion of any swap or cap transaction. Early termination of a swap could result in a termination payment by or to the Fund. Early termination of a cap could result in a termination payment to the Fund. The Fund intends to segregate with its custodian cash or liquid securities having a value at least equal to the Fund's net payment obligations under any swap transaction, marked-to-market daily. Currently, certain categories of interest rate swaps are subject to mandatory clearing, and more are expected to be cleared in the future. The counterparty risk for cleared derivatives is generally lower than for uncleared OTC derivative transactions because generally a clearing organization becomes substituted for each counterparty to a cleared derivative contract and, in effect, guarantees the parties' performance under the contract as each party to a trade looks only to the clearing house for performance of financial obligations. However, there can be no assurance that a clearing house, or its members, will satisfy the clearing house's obligations to the Fund. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Market Discount Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Market Discount Risk. The Fund's common shares have traded both at a premium and at a discount relative to net asset value. Common shares of closed-end investment companies frequently trade at a discount from net asset value, but in some cases trade above net asset value. The risk of the Fund's common shares trading at a discount is a risk separate from the risk of a decline in the Fund's net asset value as a result of investment activities. The Fund's net asset value may be reduced immediately following this offering by the offering costs for common shares or other securities, which will be borne entirely by all common shareholders. Whether shareholders will realize a gain or loss upon the sale of the Fund's common shares depends upon whether the market value of the shares at the time of sale is above or below the price the shareholder paid, taking into account transaction costs for the shares, and is not directly dependent upon the Fund's net asset value. Because the market value of the Fund's common shares will be determined by factors such as the relative demand for and supply of the shares in the market, general market conditions and other factors beyond the control of the Fund, the Fund cannot predict whether its common shares will trade at, below or above the Fund's net asset value, or below or above the public offering price for the common shares. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Market Impact Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Market Impact Risk. The sale of our common shares (or the perception that such sales may occur) may have an adverse effect on prices in the secondary market for our common shares. An increase in the number of common shares available may put downward pressure on the market price for our common shares. These sales also might make it more difficult for us to sell additional equity securities in the future at a time and price the Fund deems appropriate. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reduction Of Leverage Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Reduction of Leverage Risk. We have previously taken, and may in the future take, action to reduce the amount of leverage employed by the Fund. Reduction of the leverage employed by the Fund, including by redemption of preferred shares, will in turn reduce the amount of assets available for investment in portfolio securities. This reduction in leverage may negatively impact our financial performance, including our ability to sustain current levels of distributions on common shares. The Board reserves the right to change the amount and type of leverage that the Fund uses, and reserves the right to implement changes to the Fund's borrowings that it believes are in the best long-term interests of the Fund and its shareholders, even if such changes impose a higher interest rate or other costs or impacts over the intermediate, or short-term time period. There is no guarantee that the Fund will maintain leverage at the current rate, and the Board reserves the right to raise, decrease, or eliminate the Fund's leverage exposure. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Decline In Net Asset Value Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Decline in Net Asset Value Risk. A material decline in the Fund's NAV may impair our ability to maintain required levels of asset coverage for outstanding borrowings or any debt securities or preferred shares. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Early Redemption Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Early Redemption Risk. The Fund may voluntarily redeem preferred shares or may be forced to redeem preferred shares to meet regulatory requirements and the asset coverage requirements of the preferred shares. Such redemptions may be at a time that is unfavorable to holders of the preferred shares. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Inflation Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Inflation Risk. Inflation is the reduction in the purchasing power of money resulting from an increase in the price of goods and services. Inflation risk is the risk that the inflation adjusted or "real" value of an investment in preferred stock or debt securities or the income from that investment will be worth less in the future. As inflation occurs, the real value of the preferred stock or debt securities and the dividend payable to holders of preferred stock or interest payable to holders of debt securities declines. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest Rate Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Interest Rate Risk. Rising market interest rates could impact negatively the value of our investment portfolio, reducing the amount of assets serving as asset coverage for the senior securities. Rising market interest rates could also reduce the value of the Fund's senior securities. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Market Discount Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Market Discount Risk. The market price of exchange-listed preferred shares that the Fund may issue may also be affected by such factors as the Fund's use of leverage, dividend stability, portfolio credit quality, liquidity, and the Fund's dividends paid (which are, in turn, affected by expenses), call protection for portfolio securities and interest rate movements. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ratings And Asset Coverage Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Ratings and Asset Coverage Risk. To the extent that senior securities are rated, a rating does not eliminate or necessarily mitigate the risks of investing in our senior securities, and a rating may not fully or accurately reflect all of the credit and market risks associated with that senior security. A rating agency could downgrade the rating of our shares of preferred stock or debt securities, which may make such securities less liquid in the secondary market, though potentially with higher resulting interest rates. If a rating agency downgrades the rating assigned to a senior security, we may alter our portfolio or redeem the senior security. We may voluntarily redeem senior securities under certain circumstances. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Secondary Market Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Secondary Market Risk. The market value of exchange-listed preferred shares that the Fund may issue will be determined by factors such as the relative demand for and supply of the preferred shares in the market, general market conditions and other factors beyond the control of the Fund. It may be difficult to predict the trading patterns of preferred shares, including the effective costs of trading. There is a risk that the market for preferred shares may be thinly traded and relatively illiquid compared to the market for other types of securities. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Leverage Risk [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
General Description of Registrant [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Risk [Text Block] |  | Senior Leverage Risk. Preferred shares will be junior in liquidation and with respect to distribution rights to debt securities and any other borrowings. Senior securities representing indebtedness may constitute a substantial lien and burden on preferred shares by reason of their prior claim against our income and against our net assets in liquidation. We may not be permitted to declare dividends or other distributions with respect to any series of preferred shares unless at such time we meet applicable asset coverage requirements and the payment of principal or interest is not in default with respect to any borrowings. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Contact [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cover [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Entity Address, Address Line One |  | 2020 Calamos Court |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Entity Address, City or Town |  | Naperville |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Entity Address, State or Province |  | IL |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Entity Address, Postal Zip Code |  | 60563 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Contact Personnel Name |  | John P |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Financial Highlights [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Securities Amount |  |  |  |  |  |  | $ 314,650,000 |  |  |  |  |  |  |  | $ 314,400,000 |  |  |  |  |  |  |  | $ 314,650,000 |  | $ 314,400,000 |  | $ 339,400,000 | $ 399,400,000 | $ 288,400,000 | $ 277,400,000 | $ 288,000,000 | $ 275,000,000 | $ 306,000,000 | $ 353,000,000 |
Senior Securities Coverage per Unit | [13] |  |  |  |  |  | $ 3,835 |  |  |  |  |  |  |  | $ 3,563 |  |  |  |  |  |  |  | $ 3,835 |  | $ 3,563 |  | $ 3,630 | $ 4,116 | $ 4,431 | $ 4,080 | $ 3,921 | $ 4,265 | $ 3,454 | $ 3,316 |
Mandatory Redeemable Preferred Shares [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Financial Highlights [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Securities Amount |  |  |  |  |  |  | $ 132,750,000 |  |  |  |  |  |  |  | $ 133,000,000 |  |  |  |  |  |  |  | $ 132,750,000 |  | $ 133,000,000 |  | $ 133,000,000 | $ 133,000,000 | $ 100,000,000 | $ 100,000,000 | $ 100,000,000 | $ 100,000,000 |  |  |
Senior Securities Coverage per Unit | [14] |  |  |  |  |  | $ 227 |  |  |  |  |  |  |  | $ 211 |  |  |  |  |  |  |  | $ 227 |  | $ 211 |  | $ 232 | $ 309 | $ 319 | $ 283 | $ 282 | $ 293 |  |  |
Preferred Stock Liquidating Preference | [15] |  |  |  |  |  | $ 25 |  |  |  |  |  |  |  | $ 25 |  |  |  |  |  |  |  | 25 |  | 25 |  | 25 | 25 | 25 | 25 | 25 | 25 |  |  |
Senior Securities Average Market Value per Unit | [16] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 25 |  | $ 25 |  | $ 25 | $ 25 | $ 25 | $ 25 | $ 25 | $ 25 |  |  |
Common Shares [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital Stock, Long-Term Debt, and Other Securities [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Security Title [Text Block] |  | Common Shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Security Voting Rights [Text Block] |  | Common shareholders are entitled to one vote for each share held. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Security Liquidation Rights [Text Block] |  | Shareholders are entitled to share pro rata in the net assets of the Fund available for distribution to common shareholders upon liquidation of the Fund. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Security Preemptive and Other Rights [Text Block] |  | Common shares, when issued and outstanding, will be legally issued, fully paid and non-assessable and will have no preemptive or conversion rights or rights to cumulative voting, except as described below. The Board has not granted such common shares conversion rights. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Securities [Table Text Block] |  |  | Common Shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Held [Shares] |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Not Held [Shares] |  |  | 76,312,702 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Shares [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital Stock, Long-Term Debt, and Other Securities [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Security Title [Text Block] |  | Preferred Shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Security Voting Rights [Text Block] |  | The 1940 Act requires that the holders of any preferred shares, voting separately as a single class, have the right to elect at least two Trustees at all times. The remaining Trustees will be elected by holders of common shares and preferred shares, voting together as a single class. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Security Liquidation Rights [Text Block] |  | In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Fund, the holders of preferred shares will be entitled to receive a preferential liquidating distribution, which is expected to equal the original purchase price per preferred share plus accumulated and unpaid dividends, whether or not declared, before any distribution of assets is made to holders of common shares. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Security Obligations of Ownership [Text Block] |  | (1) adopt any plan of reorganization that would adversely affect the preferred shares, and (2) take any action requiring a vote of security holders under Section 13(a) of the 1940 Act, including, among other things, changes in the Fund's subclassification as a closed-end investment company or changes in its fundamental investment restrictions. See "Certain Provisions of the Agreement and Declaration of Trust and By-Laws, Including Antitakeover Provisions." |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rights Subject to Other than Majority Vote [Text Block] |  | In addition, subject to the prior rights, if any, of the holders of any other class of senior securities outstanding, the holders of any preferred shares have the right to elect a majority of the Trustees at any time two years' accumulated dividends on any preferred shares are unpaid. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
MRPS-Series C [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital Stock, Long-Term Debt, and Other Securities [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Securities [Table Text Block] |  |  | MRPS-Series C |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Authorized [Shares] |  |  | 1,340,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Held [Shares] |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Not Held [Shares] |  |  | 1,340,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
MRPS-Series D [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital Stock, Long-Term Debt, and Other Securities [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Securities [Table Text Block] |  |  | MRPS-Series D |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Authorized [Shares] |  |  | 1,320,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Held [Shares] |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Not Held [Shares] |  |  | 1,320,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
MRPS-Series E [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital Stock, Long-Term Debt, and Other Securities [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Securities [Table Text Block] |  |  | MRPS-Series E |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Authorized [Shares] |  |  | 1,330,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Held [Shares] |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Not Held [Shares] |  |  | 1,330,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
MRPS-Series G [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Capital Stock, Long-Term Debt, and Other Securities [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Securities [Table Text Block] |  |  | MRPS-Series G |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Authorized [Shares] |  |  | 1,320,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Held [Shares] |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding Security, Not Held [Shares] |  |  | 1,320,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
[1] | If the securities to which this prospectus relates are sold to or through underwriters, the prospectus supplement will set forth any applicable sales load and the estimated offering expenses borne by us.
[2] | Shareholders will pay a $15.00 transaction fee plus a $0.02 per share brokerage charge if they direct the Plan Agent (as defined below) to sell common shares held in a Plan account. In addition, each participant will pay a pro rata share of brokerage commissions incurred with respect to the Plan Agent's open-market purchases in connection with the reinvestment of dividends or distributions. If a participant elects to have the Plan Agent sell part or all of his or her common shares and remit the proceeds, such participant will be charged his or her pro rata share of brokerage commissions on the shares sold. See "Dividends and Distributions on Common Shares; Automatic Dividend Reinvestment Plan."
[3] | The Fund pays Calamos an annual management fee, payable monthly in arrears, for its investment management services in an amount equal to 0.80% of the Fund's average weekly managed assets. In accordance with the requirements of the Commission, the table above shows the Fund's management fee as a percentage of average net assets attributable to common shareholders. By showing the management fee as a percentage of net assets, the management fee is not expressed as a percentage of all of the assets the Fund intends to invest. For purposes of the table, the management fee has been converted to 1.26% of the Fund's average weekly net assets as of January 31, 2025 by dividing the total dollar amount of the management fee by the Fund's average weekly net assets (managed assets less outstanding leverage).
[4] | Reflects interest expense paid on $254 million in average borrowings under the SSB Agreement, plus $61 million in additional average structural leverage related to certain securities lending programs, as described under "Leverage."
[5] | Reflects estimated dividend expense on $133 million aggregate liquidation preference of mandatory redeemable preferred shares outstanding. See "Leverage."
[6] | "Other Expenses" are based on estimated amounts for the Fund's current fiscal year.
[7] | The example does not include sales load or estimated offering costs, which would cause the expenses shown in the example to increase. In connection with an offering of common shares, the applicable prospectus supplement will set forth an example including sales load and estimated offering costs.
[8] | Calculated by subtracting the Fund's total liabilities (not including Notes payable and Mandatory Redeemable Preferred Shares) from the Fund's total assets and dividing this by the amount of Notes payable outstanding, and by multiplying the result by 1,000.
[9] | Includes interest expense on the borrowings under the SSB Agreement, accrued at interest rates in effect on January 31, 2025 of 5.35%, and dividend expense on the MRP Shares.
[10] | Based on high and low closing market price per share during the respective quarter and does not reflect commissions.
[11] | Premium and discount information is shown for the days when the Fund experienced its high and low closing market prices, respectively, per share during the respective quarter.
[12] | Based on the NAV calculated on the close of business on the last business day of each calendar quarter.
[13] | Calculated by subtracting the Fund's total liabilities (not including notes payable and MRPS) from the Fund's total assets and dividing this by the amount of notes payable outstanding, and by multiplying the result by 1,000.
[14] | Calculated by subtracting the Fund's total liabilities (not including MRPS) from the Fund's total assets and dividing this by the number of MRPS outstanding, and by multiplying the result by 25.
[15] | "Liquidating Preference per Preferred Share" means the amount to which a holder of preferred shares would be entitled upon the liquidation of the Fund in preference to common shareholders, expressed as a dollar amount per preferred share.
[16] | The MRPS are not listed on any exchange or automated quotation system. The MRPS are considered debt of the issuer; and the liquidation preference approximates fair value.

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