Benefit Plans (Defined Benefit Pension And Other Postretirement Benefits Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 11	$ 11	$ 10
Interest cost	34	43	50
Expected return on plan assets	(69)	(70)	(60)
Amortization of prior service cost (credit)	0	0	(1)
Amortization of actuarial loss	39	34	36
Settlement losses	0	12	0
Total	15	30	35
Other Postretirement Benefits Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	3	3
Interest cost	5	7	9
Expected return on plan assets	(5)	(5)	(5)
Amortization of prior service cost (credit)	0	0	0
Amortization of actuarial loss	5	3	3
Settlement losses	0	0	0
Total	9	8	10
IPL [Member] | Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	7	7	6
Interest cost	16	20	23
Expected return on plan assets	(32)	(33)	(28)
Amortization of actuarial loss	17	15	15
Settlement losses	0	7	0
Total	8	16	16
IPL [Member] | Other Postretirement Benefits Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	1
Interest cost	2	3	3
Expected return on plan assets	(3)	(4)	(4)
Amortization of actuarial loss	2	1	2
Settlement losses	0	0	0
Total	2	1	2
WPL [Member] | Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	4	3
Interest cost	15	19	21
Expected return on plan assets	(31)	(31)	(26)
Amortization of prior service cost (credit)	0	0	0
Amortization of actuarial loss	19	16	18
Total	7	8	16
WPL [Member] | Other Postretirement Benefits Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	2	1
Interest cost	2	3	3
Expected return on plan assets	0	(1)	(1)
Amortization of prior service cost (credit)	0	(1)	0
Amortization of actuarial loss	2	2	2
Total	$ 5	$ 5	$ 5