Property, Plant and Equipment (Equity and Debt AFUDC) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Allowance for funds used during construction	$ 60	$ 25	$ 55
Equity [Member]
Property, Plant and Equipment [Line Items]
Allowance for funds used during construction	44	18	39
Debt [Member]
Property, Plant and Equipment [Line Items]
Allowance for funds used during construction	16	7	16
IPL [Member]
Property, Plant and Equipment [Line Items]
Allowance for funds used during construction	11	9	24
IPL [Member] | Equity [Member]
Property, Plant and Equipment [Line Items]
Allowance for funds used during construction	8	7	17
IPL [Member] | Debt [Member]
Property, Plant and Equipment [Line Items]
Allowance for funds used during construction	3	2	7
WPL [Member]
Property, Plant and Equipment [Line Items]
Allowance for funds used during construction	49	16	31
WPL [Member] | Equity [Member]
Property, Plant and Equipment [Line Items]
Allowance for funds used during construction	36	11	22
WPL [Member] | Debt [Member]
Property, Plant and Equipment [Line Items]
Allowance for funds used during construction	$ 13	$ 5	$ 9