Benefit Plans (Defined Benefit Pension And Other Postretirement Benefits Plans) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1	$ 2	$ 3	$ 4
Interest cost	12	12	34	35
Expected return on plan assets	(14)	(14)	(41)	(40)
Amortization of prior service credit	0	(1)	0	(1)
Amortization of actuarial loss	6	7	18	21
Total	5	6	14	19
OPEB Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	2	2
Interest cost	2	3	6	7
Expected return on plan assets	(2)	(2)	(4)	(4)
Amortization of prior service credit	0	0	0	0
Amortization of actuarial loss	0	0	0	1
Total	1	2	4	6
IPL [Member] | Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	0	2	2
Interest cost	5	6	15	16
Expected return on plan assets	(7)	(6)	(20)	(19)
Amortization of actuarial loss	2	2	7	8
Total	1	2	4	7
IPL [Member] | OPEB Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	1	1	3	3
Expected return on plan assets	(1)	(1)	(3)	(3)
Amortization of actuarial loss	0	0	0	1
Total	0	0	0	1
WPL [Member] | Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	1	1
Interest cost	5	5	15	15
Expected return on plan assets	(6)	(5)	(18)	(16)
Amortization of actuarial loss	3	3	9	10
Total	2	3	7	10
WPL [Member] | OPEB Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	1	0	1
Interest cost	1	1	3	3
Expected return on plan assets	(1)	(1)	(1)	(1)
Amortization of actuarial loss	0	0	0	0
Total	$ 0	$ 1	$ 2	$ 3