Valuation And Qualifying Accounts and Reserves (Details) - Accumulated Provision for Uncollectible Accounts [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	$ 18.0	$ 7.0	$ 10.0
Charged to Expense	12.0	25.0	17.0
Charged to Other Accounts	0.0	9.0	2.0
Deductions	19.0	23.0	22.0
Ending Balance	11.0	18.0	7.0
IPL [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	1.0	1.0	3.0
Charged to Expense	6.0	18.0	16.0
Charged to Other Accounts	0.0	0.0	0.0
Deductions	6.0	18.0	18.0
Ending Balance	1.0	1.0	1.0
WPL [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	17.0	6.0	7.0
Charged to Expense	6.0	7.0	1.0
Charged to Other Accounts	0.0	9.0	2.0
Deductions	13.0	5.0	4.0
Ending Balance	$ 10.0	$ 17.0	$ 6.0