Benefit Plans (Defined Benefit Pension And Other Postretirement Benefits Plans) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1	$ 1	$ 2	$ 2
Interest cost	11	12	22	23
Expected return on plan assets	(14)	(13)	(27)	(26)
Amortization of actuarial loss	6	7	12	14
Total	4	7	9	13
OPEB Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	0	1	1
Interest cost	2	2	4	4
Expected return on plan assets	(1)	(1)	(2)	(2)
Amortization of actuarial loss	0	1	0	1
Total	2	2	3	4
IPL [Member] | Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	1	1	2
Interest cost	5	5	10	10
Expected return on plan assets	(6)	(6)	(13)	(13)
Amortization of actuarial loss	3	3	5	6
Total	2	3	3	5
IPL [Member] | OPEB Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	1	1	2	2
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	1	1
Interest cost	5	5	10	10
Expected return on plan assets	(6)	(6)	(12)	(11)
Amortization of actuarial loss	3	4	6	7
Total	3	4	5	7
WPL [Member] | OPEB Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	1	1	2	2
Expected return on plan assets	0	0	0	0
Amortization of actuarial loss	0	0	0	0
Total	$ 1	$ 1	$ 2	$ 2