Segments Of Business (Schedule Of Segments Of Business) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Revenues	$ 1,077	$ 1,068
Operating income	222	248
Net income attributable to common shareowners	163	192
Net income	163	192
IPL [Member]
Segment Reporting Information [Line Items]
Revenues	549	550
Operating income	96	110
Net income	72	87
WPL [Member]
Segment Reporting Information [Line Items]
Revenues	506	496
Operating income	121	131
Net income	88	92
Electric [Member]
Segment Reporting Information [Line Items]
Revenues	768	773
Operating income	163	181
Electric [Member] | IPL [Member]
Segment Reporting Information [Line Items]
Revenues	388	400
Operating income	66	75
Electric [Member] | WPL [Member]
Segment Reporting Information [Line Items]
Revenues	380	373
Operating income	97	106
Gas [Member]
Segment Reporting Information [Line Items]
Revenues	276	262
Operating income	50	57
Gas [Member] | IPL [Member]
Segment Reporting Information [Line Items]
Revenues	150	139
Operating income	27	32
Gas [Member] | WPL [Member]
Segment Reporting Information [Line Items]
Revenues	126	123
Operating income	23	25
Other Utility [Member]
Segment Reporting Information [Line Items]
Revenues	11	11
Operating income	4	3
Other Utility [Member] | IPL [Member]
Segment Reporting Information [Line Items]
Revenues	11	11
Operating income	3	3
Other Utility [Member] | WPL [Member]
Segment Reporting Information [Line Items]
Revenues	0	0
Operating income	1	0
Utility Business [Member]
Segment Reporting Information [Line Items]
Revenues	1,055	1,046
Operating income	217	241
Net income attributable to common shareowners	160	179
ATC Holdings, Non-Utility, Parent and Other [Member]
Segment Reporting Information [Line Items]
Revenues	22	22
Operating income	5	7
Net income attributable to common shareowners	$ 3	$ 13