Derivative Instruments (Fair Value Of Financial Instruments) (Details) - Commodity Contracts [Member] - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Current derivative assets	$ 28	$ 111
Non-current derivative assets	94	126
Current derivative liabilities	65	59
Non-current derivative liabilities	30	20
IPL [Member]
Derivatives, Fair Value [Line Items]
Current derivative assets	17	69
Non-current derivative assets	52	69
Current derivative liabilities	26	40
Non-current derivative liabilities	8	6
WPL [Member]
Derivatives, Fair Value [Line Items]
Current derivative assets	11	42
Non-current derivative assets	42	57
Current derivative liabilities	39	19
Non-current derivative liabilities	$ 22	$ 14