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v3.23.3

Debt (Other Short-Term Borrowings) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022
Debt [Line Items] |  |  |  |
Maximum amount outstanding (based on daily outstanding balances) | $ 474 | $ 449 | $ 793 | $ 577
Average amount outstanding (based on daily outstanding balances) | $ 440 | $ 353 | $ 367 | $ 377
Weighted average interest rates | 5.50% | 2.40% | 5.10% | 1.20%
IPL [Member] |  |  |  |
Debt [Line Items] |  |  |  |
Maximum amount outstanding (based on daily outstanding balances) | $ 7 | $ 0 | $ 70 | $ 0
Average amount outstanding (based on daily outstanding balances) | $ 0 | $ 0 | $ 2 | $ 0
Weighted average interest rates | 5.50% | 0.00% | 5.30% | 0.00%
WPL [Member] |  |  |  |
Debt [Line Items] |  |  |  |
Maximum amount outstanding (based on daily outstanding balances) | $ 125 | $ 251 | $ 349 | $ 252
Average amount outstanding (based on daily outstanding balances) | $ 86 | $ 110 | $ 135 | $ 160
Weighted average interest rates | 5.40% | 2.00% | 4.90% | 0.90%

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