Income Taxes (Schedule Of Components Of Income Tax) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Current tax expense (benefit):
Federal	$ 13	$ (3)	$ 7
State	(10)	(6)	2
Deferred tax expense (benefit):
Federal	60	100	109
State	15	36	28
Production tax credits	(177)	(121)	(123)
Investment tax credits	(15)	(1)	(1)
Provision recorded as a change in accrued interest	0	(1)	0
Income tax expense (benefit)	(114)	4	22
IPL [Member]
Current tax expense (benefit):
Federal	(19)	(44)	(29)
State	(19)	(21)	(8)
Deferred tax expense (benefit):
Federal	38	87	91
State	(17)	17	1
Production tax credits	(108)	(95)	(105)
Investment tax credits	(4)	(1)	0
Provision recorded as a change in accrued interest	0	(1)	0
Income tax expense (benefit)	(129)	(58)	(50)
WPL [Member]
Current tax expense (benefit):
Federal	37	48	46
State	23	25	16
Deferred tax expense (benefit):
Federal	24	10	10
State	7	3	12
Production tax credits	(69)	(26)	(18)
Investment tax credits	(11)	0	0
Provision recorded as a change in accrued interest	0	0	0
Income tax expense (benefit)	$ 11	$ 60	$ 66