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Debt | 6 Months Ended
--- | ---
Jun. 30, 2023
Debt [Line Items] |
Debt | DEBT NOTE 7(a) Short-term Debt - In March 2023, Alliant Energy, IPL and WPL extended their single credit facility agreement, which currently expires in December 2027, and reallocated credit facility capacity amounts to $450 million for Alliant Energy at the parent company level, $250 million for IPL and $300 million for WPL, within the $1 billion total commitment. Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper classified as short-term debt was as follows (dollars in millions):
June 30, 2023 | Alliant Energy |  | IPL |  | WPL
Amount outstanding | $391 |  | $— |  | $44
Weighted average interest rates | 5.3% |  | —% |  | 5.2%
Available credit facility capacity (a) | $554 |  | $195 |  | $256
| Alliant Energy |  | IPL |  | WPL
Three Months Ended June 30 | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Maximum amount outstanding (based on daily outstanding balances) | $391 |  | $441 |  | $70 |  | $— |  | $91 |  | $222
Average amount outstanding (based on daily outstanding balances) | $88 |  | $337 |  | $6 |  | $— |  | $18 |  | $166
Weighted average interest rates | 5.3% |  | 1.0% |  | 5.3% |  | —% |  | 5.2% |  | 0.9%
Six Months Ended June 30 |  |  |  |  |  |  |  |  |  |  |
Maximum amount outstanding (based on daily outstanding balances) | $793 |  | $577 |  | $70 |  | $— |  | $349 |  | $252
Average amount outstanding (based on daily outstanding balances) | $330 |  | $390 |  | $3 |  | $— |  | $160 |  | $185
Weighted average interest rates | 4.8% |  | 0.6% |  | 5.3% |  | —% |  | 4.8% |  | 0.5%
(a)Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at June 30, 2023. In January 2023, AEF received $50 million of proceeds from its December 2022 term loan credit agreement, which was classified as “Other short-term borrowings” on Alliant Energy’s balance sheet as of June 30, 2023. NOTE 7(b) Long-term Debt - In June 2023, AEF retired its $400 million 3.75% senior notes. In March 2023, WPL issued $300 million of 4.95% debentures due 2033. WPL’s debentures were issued as green bonds, and an amount equal to or in excess of the net proceeds will be allocated or disbursed for the development and acquisition of its solar EGUs. As of June 30, 2023, $55 million of commercial paper was recorded in “Long-term debt, net” on Alliant Energy’s and IPL’s balance sheets due to the existence of the long-term single credit facility that back-stops this commercial paper balance, along with Alliant Energy’s and IPL’s intent and ability to refinance these balances on a long-term basis. As of June 30, 2023, this commercial paper balance had a 5% interest rate. Convertible Senior Notes - In March 2023, Alliant Energy issued $575 million of 3.875% convertible senior notes (the Notes), which are senior unsecured obligations, and used the net proceeds from the issuance for general corporate purposes. The Notes will mature on March 15, 2026 unless earlier converted or repurchased, and no sinking fund is provided for the Notes. Alliant Energy may not redeem the Notes prior to the maturity date. Holders may convert their Notes at their option at any time prior to the close of business on the business day immediately preceding December 15, 2025 only under the following circumstances: •during any calendar quarter commencing after the calendar quarter ending on June 30, 2023 (and only during such calendar quarter), if the last reported sale price of Alliant Energy’s common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day during such period; •during the 5 business day period after any 10 consecutive trading day period (the “measurement period”) in which the trading price (as defined in the related Indenture) per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of Alliant Energy’s common stock and the conversion rate on each such trading day; or •upon the occurrence of specified corporate events. On or after December 15, 2025 until the close of business on the business day immediately preceding the maturity date, holders may convert all or any portion of their Notes at any time, regardless of the foregoing circumstances. Upon conversion of the Notes, Alliant Energy will pay cash up to the aggregate principal amount of the Notes to be converted and pay or deliver, as the case may be, cash, shares of its common stock or a combination of cash and shares of its common stock, at its election, in respect of the remainder, if any, of its conversion obligation in excess of the aggregate principal amount of the Notes being converted. The initial conversion rate is 15.5461 shares of common stock per $1,000 principal amount of Notes (equivalent to an initial conversion price of approximately $64.32 per share of Alliant Energy’s common stock). The conversion rate is subject to adjustment in some events but will not be adjusted for any accrued and unpaid interest. In addition, following certain corporate events that occur prior to the maturity date, Alliant Energy will, in certain circumstances, increase the conversion rate for a holder who elects to convert its Notes in connection with such a corporate event. If Alliant Energy undergoes a fundamental change (as defined in the related Indenture), then, subject to certain conditions, holders of the Notes may require Alliant Energy to repurchase for cash all or any portion of its Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. As of June 30, 2023, the conditions allowing holders of the Notes to convert their Notes were not met, and as a result, the Notes were classified as “Long-term debt, net” on Alliant Energy’s balance sheet. As of June 30, 2023, the net carrying amount of the Notes was $566 million, with unamortized debt issuance costs of $9 million, and the estimated fair value (Level 2) of the Notes was $573 million. As of June 30, 2023, there were no shares of Alliant Energy’s common stock related to the potential conversion of the Notes included in diluted EPS based on Alliant Energy’s average stock prices and the relevant terms of the Notes.
IPL [Member] |
Debt [Line Items] |
Debt | DEBT NOTE 7(a) Short-term Debt - In March 2023, Alliant Energy, IPL and WPL extended their single credit facility agreement, which currently expires in December 2027, and reallocated credit facility capacity amounts to $450 million for Alliant Energy at the parent company level, $250 million for IPL and $300 million for WPL, within the $1 billion total commitment. Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper classified as short-term debt was as follows (dollars in millions):
June 30, 2023 | Alliant Energy |  | IPL |  | WPL
Amount outstanding | $391 |  | $— |  | $44
Weighted average interest rates | 5.3% |  | —% |  | 5.2%
Available credit facility capacity (a) | $554 |  | $195 |  | $256
| Alliant Energy |  | IPL |  | WPL
Three Months Ended June 30 | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Maximum amount outstanding (based on daily outstanding balances) | $391 |  | $441 |  | $70 |  | $— |  | $91 |  | $222
Average amount outstanding (based on daily outstanding balances) | $88 |  | $337 |  | $6 |  | $— |  | $18 |  | $166
Weighted average interest rates | 5.3% |  | 1.0% |  | 5.3% |  | —% |  | 5.2% |  | 0.9%
Six Months Ended June 30 |  |  |  |  |  |  |  |  |  |  |
Maximum amount outstanding (based on daily outstanding balances) | $793 |  | $577 |  | $70 |  | $— |  | $349 |  | $252
Average amount outstanding (based on daily outstanding balances) | $330 |  | $390 |  | $3 |  | $— |  | $160 |  | $185
Weighted average interest rates | 4.8% |  | 0.6% |  | 5.3% |  | —% |  | 4.8% |  | 0.5%
(a)Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at June 30, 2023. In January 2023, AEF received $50 million of proceeds from its December 2022 term loan credit agreement, which was classified as “Other short-term borrowings” on Alliant Energy’s balance sheet as of June 30, 2023. NOTE 7(b) Long-term Debt - In June 2023, AEF retired its $400 million 3.75% senior notes. In March 2023, WPL issued $300 million of 4.95% debentures due 2033. WPL’s debentures were issued as green bonds, and an amount equal to or in excess of the net proceeds will be allocated or disbursed for the development and acquisition of its solar EGUs. As of June 30, 2023, $55 million of commercial paper was recorded in “Long-term debt, net” on Alliant Energy’s and IPL’s balance sheets due to the existence of the long-term single credit facility that back-stops this commercial paper balance, along with Alliant Energy’s and IPL’s intent and ability to refinance these balances on a long-term basis. As of June 30, 2023, this commercial paper balance had a 5% interest rate.
WPL [Member] |
Debt [Line Items] |
Debt | DEBT NOTE 7(a) Short-term Debt - In March 2023, Alliant Energy, IPL and WPL extended their single credit facility agreement, which currently expires in December 2027, and reallocated credit facility capacity amounts to $450 million for Alliant Energy at the parent company level, $250 million for IPL and $300 million for WPL, within the $1 billion total commitment. Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper classified as short-term debt was as follows (dollars in millions):
June 30, 2023 | Alliant Energy |  | IPL |  | WPL
Amount outstanding | $391 |  | $— |  | $44
Weighted average interest rates | 5.3% |  | —% |  | 5.2%
Available credit facility capacity (a) | $554 |  | $195 |  | $256
| Alliant Energy |  | IPL |  | WPL
Three Months Ended June 30 | 2023 |  | 2022 |  | 2023 |  | 2022 |  | 2023 |  | 2022
Maximum amount outstanding (based on daily outstanding balances) | $391 |  | $441 |  | $70 |  | $— |  | $91 |  | $222
Average amount outstanding (based on daily outstanding balances) | $88 |  | $337 |  | $6 |  | $— |  | $18 |  | $166
Weighted average interest rates | 5.3% |  | 1.0% |  | 5.3% |  | —% |  | 5.2% |  | 0.9%
Six Months Ended June 30 |  |  |  |  |  |  |  |  |  |  |
Maximum amount outstanding (based on daily outstanding balances) | $793 |  | $577 |  | $70 |  | $— |  | $349 |  | $252
Average amount outstanding (based on daily outstanding balances) | $330 |  | $390 |  | $3 |  | $— |  | $160 |  | $185
Weighted average interest rates | 4.8% |  | 0.6% |  | 5.3% |  | —% |  | 4.8% |  | 0.5%
(a)Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at June 30, 2023. In January 2023, AEF received $50 million of proceeds from its December 2022 term loan credit agreement, which was classified as “Other short-term borrowings” on Alliant Energy’s balance sheet as of June 30, 2023. NOTE 7(b) Long-term Debt - In June 2023, AEF retired its $400 million 3.75% senior notes. In March 2023, WPL issued $300 million of 4.95% debentures due 2033. WPL’s debentures were issued as green bonds, and an amount equal to or in excess of the net proceeds will be allocated or disbursed for the development and acquisition of its solar EGUs.

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