Benefit Plans (Defined Benefit Pension And Other Postretirement Benefits Plans) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2	$ 3	$ 4	$ 7
Interest cost	12	9	35	27
Expected return on plan assets	(14)	(18)	(40)	(52)
Amortization of prior service credit	(1)	0	(1)	0
Amortization of actuarial loss	7	8	21	24
Total	6	2	19	6
OPEB Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	0	2	2
Interest cost	3	1	7	4
Expected return on plan assets	(2)	0	(4)	(3)
Amortization of prior service credit	0	0	0	0
Amortization of actuarial loss	0	1	1	2
Total	2	2	6	5
IPL [Member] | Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	1	2	4
Interest cost	6	4	16	12
Expected return on plan assets	(6)	(7)	(19)	(23)
Amortization of actuarial loss	2	3	8	10
Total	2	1	7	3
IPL [Member] | OPEB Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	1
Interest cost	1	1	3	2
Expected return on plan assets	(1)	(1)	(3)	(3)
Amortization of actuarial loss	0	0	1	0
Total	0	0	1	0
WPL [Member] | Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	1	2
Interest cost	5	4	15	12
Expected return on plan assets	(5)	(7)	(16)	(23)
Amortization of actuarial loss	3	4	10	12
Total	3	1	10	3
WPL [Member] | OPEB Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	0	1	0
Interest cost	1	1	3	2
Expected return on plan assets	(1)	0	(1)	0
Amortization of actuarial loss	0	0	0	1
Total	$ 1	$ 1	$ 3	$ 3