Income Taxes (Schedule Of Components Of Income Tax) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current tax expense (benefit):
Federal	$ 7	$ 1	$ 1
State	2	3	8
Deferred tax expense (benefit):
Federal	109	9	22
State	28	15	8
Production tax credits	(123)	(101)	(95)
Investment tax credits	(1)	(1)	(1)
Income tax expense (benefit)	22	(74)	(57)
IPL [Member]
Current tax expense (benefit):
Federal	(29)	(21)	6
State	(8)	(1)	(1)
Deferred tax expense (benefit):
Federal	91	73	30
State	1	0	(2)
Production tax credits	(105)	(87)	(80)
Investment tax credits	0	0	0
Income tax expense (benefit)	(50)	(36)	(47)
WPL [Member]
Current tax expense (benefit):
Federal	46	22	(11)
State	16	6	7
Deferred tax expense (benefit):
Federal	10	(75)	(9)
State	12	11	10
Production tax credits	(18)	(14)	(15)
Investment tax credits	0	(1)	(1)
Income tax expense (benefit)	$ 66	$ (51)	$ (19)