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Note 7 - Borrowings (Details Textual) - USD ($) $ / shares in Units, $ in Thousands |  |  |  | 3 Months Ended | 12 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
May 24, 2023 | Feb. 25, 2022 | Apr. 21, 2020 | Mar. 31, 2024 | Mar. 31, 2023 | Dec. 31, 2023 | Jun. 29, 2023 | Nov. 09, 2022 | Jun. 15, 2022 | Mar. 30, 2021 | Aug. 13, 2019
Restricted Investments |  |  |  | $ 2,533 |  | $ 2,642 |  |  |  |  |
Long-Term Debt, Gross |  |  |  | 456,000 |  | 466,000 |  |  |  |  |
Debt Instrument, Face Amount |  |  |  | $ 615,000 |  | 615,000 |  |  |  |  |
Key Facility [Member] |  |  |  |  |  |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity, Accordian Feature |  |  |  |  |  |  | $ 150,000 |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity |  |  |  |  |  |  | $ 300,000 |  |  |  |
Line of Credit Facility, Advance Rate of Eligible Debt Investments |  |  |  |  |  |  | 60.00% |  |  |  |
Long-Term Debt, Weighted Average Interest Rate, over Time |  |  |  | 8.75% | 7.94% |  |  |  |  |  |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage |  |  |  | 0.50% |  |  |  |  |  |  |
Line of Credit Facility, Current Borrowing Capacity |  |  |  | $ 90,000 |  | 80,000 |  |  |  |  |
Line of Credit Facility, Remaining Borrowing Capacity |  |  |  | 20,300 |  | 25,000 |  |  |  |  |
Long-Term Debt, Gross |  |  |  | 60,000 |  | 70,000 |  |  |  |  |
Debt Instrument, Face Amount |  |  |  | $ 150,000 |  | $ 150,000 |  |  |  |  |
Key Facility [Member] | Prime Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  |  |  | 0.25% |  |  |  |  |
Debt Instrument, Variable Rate |  |  |  | 8.50% |  | 8.50% |  |  |  |  |
NYL Facility [Member] |  |  |  |  |  |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity | $ 250,000 |  | $ 100,000 |  |  |  |  |  |  |  |
Line of Credit Facility, Current Borrowing Capacity |  |  |  | $ 69,000 |  | $ 69,000 |  |  |  |  |
Line of Credit Facility, Remaining Borrowing Capacity |  |  |  | 900 |  | 17,400 |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity, Accordion Feature |  |  | $ 200,000 |  |  |  |  |  |  |  |
Line of Credit Facility, Advance Rate |  |  | 67.00% |  |  |  |  |  |  |  |
Line of Credit Facility, Change in Maximum Borrowing Capacity | $ 50,000 | $ 100,000 |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage | 4.60% |  |  |  |  |  |  |  |  |  |
Long-Term Line of Credit |  |  |  | $ 181,000 |  | 181,000 |  |  |  |  |
Line of Credit Facility, Interest Rate at Period End |  |  |  | 6.18% | 5.57% |  |  |  |  |  |
Restricted Investments |  |  |  | $ 1,400 |  | 1,400 |  |  |  |  |
Long-Term Debt, Gross |  |  |  | 181,000 |  | 181,000 |  |  |  |  |
Debt Instrument, Face Amount |  |  |  | 250,000 |  | 250,000 |  |  |  |  |
NYL Facility [Member] | USD Mid-market Swap Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 3.00% |  |  |  |  |  |  |  |  |
NYL Facility [Member] | Three Year I Curve [Member] |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate | 3.50% |  |  |  |  |  |  |  |  |  |
Asset-backed Notes 2019 [Member] |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  |  |  |  |  |  |  |  |  |  | 4.21%
Debt Instrument, Face Amount |  |  |  |  |  |  |  |  |  |  | $ 160,000
Asset-backed Notes 2022 [Member] |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  |  |  |  |  |  |  | 7.56% |  |  |
Restricted Investments |  |  |  | 1,300 |  | 1,200 |  |  |  |  |
Long-Term Debt, Gross |  |  |  | 100,000 |  | 100,000 |  |  |  |  |
Debt Instrument, Face Amount |  |  |  | 100,000 |  | 100,000 |  | $ 157,800 |  |  |
The 2026 Notes [Member] |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  |  |  |  |  |  |  |  |  | 4.875% |
Long-Term Debt, Gross |  |  |  | 57,500 |  | 57,500 |  |  |  |  |
Debt Instrument, Face Amount |  |  |  | 57,500 |  | 57,500 |  |  |  | $ 57,500 |
The 2026 Notes Underwriter Option [Member] |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  |  |  |  |  |  |  |  |  | $ 7,500 |
Debt Instrument, Convertible, Conversion Price (in dollars per share) |  |  |  |  |  |  |  |  |  | $ 25 |
The 2027 Notes [Member] |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  |  |  |  |  |  |  |  | 6.25% |  |
Long-Term Debt, Gross |  |  |  | 57,500 |  | 57,500 |  |  |  |  |
Debt Instrument, Face Amount |  |  |  | $ 57,500 |  | $ 57,500 |  |  | $ 50,000 |  |
The 2027 Notes Underwriter Option [Member] |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  |  |  |  |  |  |  |  | $ 7,500 |  |
Debt Instrument, Convertible, Conversion Price (in dollars per share) |  |  |  |  |  |  |  |  | $ 25 |  |
Minimum [Member] |  |  |  |  |  |  |  |  |  |  |
Asset Coverage to Borrowings, Ratio, Percent |  |  |  | 150.00% |  |  |  |  |  |  |
Minimum [Member] | Key Facility [Member] | Prime Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  |  |  | 4.25% |  |  |  |  |
Minimum [Member] | NYL Facility [Member] | USD Mid-market Swap Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  | 3.55% |  |  |  |  |  |  |  |
Maximum [Member] |  |  |  |  |  |  |  |  |  |  |
Asset Coverage to Borrowings, Ratio, Percent |  |  |  | 173.00% |  |  |  |  |  |  |
Maximum [Member] | NYL Facility [Member] | USD Mid-market Swap Rate [Member] |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  | 5.15% |  |  |  |  |  |  |  |

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- Definition Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -SubTopic 10 -Topic 210 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-4 + Details
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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -SubTopic 10 -Topic 210 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)(a)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 + Details
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- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
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