Valuation And Qualifying Accounts and Reserves (Details) - Accumulated Provision for Uncollectible Accounts [Member] - USD ($) $ in Millions	12 Months Ended
	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