Benefit Plans (Defined Benefit Pension And Other Postretirement Benefits Plans) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2	$ 3	$ 4	$ 6
Interest cost	9	9	18	17
Expected return on plan assets	(17)	(17)	(34)	(34)
Amortization of actuarial loss	8	9	16	19
Total	2	4	4	8
OPEB Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	2	2
Interest cost	2	1	3	2
Expected return on plan assets	(2)	(1)	(3)	(2)
Amortization of actuarial loss	0	1	1	2
Total	1	2	3	4
IPL [Member] | Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	2	3	4
Interest cost	4	4	8	8
Expected return on plan assets	(8)	(8)	(16)	(16)
Amortization of actuarial loss	4	4	7	8
Total	1	2	2	4
IPL [Member] | OPEB Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	1	1
Interest cost	0	0	1	1
Expected return on plan assets	(1)	(1)	(2)	(2)
Amortization of actuarial loss	0	1	0	1
Total	0	1	0	1
WPL [Member] | Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	2	2
Interest cost	4	4	8	8
Expected return on plan assets	(8)	(7)	(16)	(15)
Amortization of actuarial loss	4	4	8	9
Total	1	2	2	4
WPL [Member] | OPEB Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	0	1	1	1
Expected return on plan assets	0	0	0	0
Amortization of actuarial loss	1	0	1	1
Total	$ 1	$ 1	$ 2	$ 2