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Valuation And Qualifying Accounts and Reserves (Details) - Accumulated Provision for Uncollectible Accounts [Member] - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Beginning Balance | $ 7.0 | $ 11.0 | $ 18.0
Charged to Expense | 20.0 | 17.0 | 12.0
Deductions | 19.0 | 21.0 | 19.0
Ending Balance | 8.0 | 7.0 | 11.0
IPL [Member] |  |  |
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Beginning Balance | 0.0 | 1.0 | 1.0
Charged to Expense | 11.0 | 7.0 | 6.0
Deductions | 11.0 | 8.0 | 6.0
Ending Balance | 0.0 | 0.0 | 1.0
WPL [Member] |  |  |
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Beginning Balance | 7.0 | 10.0 | 17.0
Charged to Expense | 9.0 | 10.0 | 6.0
Deductions | 8.0 | 13.0 | 13.0
Ending Balance | $ 8.0 | $ 7.0 | $ 10.0

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