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v3.22.1

Segments Of Business (Schedule Of Segments Of Business) (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2022 | Mar. 31, 2021
Segment Reporting Information [Line Items] |  |
Revenues | $ 1,068 | $ 901
Operating income (loss) | 248 | 198
Net income attributable to common shareowners | 192 | 171
Net income | 192 | 174
IPL [Member] |  |
Segment Reporting Information [Line Items] |  |
Revenues | 550 | 489
Operating income (loss) | 110 | 103
Net income attributable to common shareowners | 87 | 79
Net income | 87 | 82
WPL [Member] |  |
Segment Reporting Information [Line Items] |  |
Revenues | 496 | 395
Operating income (loss) | 131 | 90
Net income | 92 | 84
Electric [Member] |  |
Segment Reporting Information [Line Items] |  |
Revenues | 773 | 701
Operating income (loss) | 181 | 147
Electric [Member] | IPL [Member] |  |
Segment Reporting Information [Line Items] |  |
Revenues | 400 | 386
Operating income (loss) | 75 | 72
Electric [Member] | WPL [Member] |  |
Segment Reporting Information [Line Items] |  |
Revenues | 373 | 315
Operating income (loss) | 106 | 75
Gas [Member] |  |
Segment Reporting Information [Line Items] |  |
Revenues | 262 | 170
Operating income (loss) | 57 | 44
Gas [Member] | IPL [Member] |  |
Segment Reporting Information [Line Items] |  |
Revenues | 139 | 91
Operating income (loss) | 32 | 30
Gas [Member] | WPL [Member] |  |
Segment Reporting Information [Line Items] |  |
Revenues | 123 | 79
Operating income (loss) | 25 | 14
Other Utility [Member] |  |
Segment Reporting Information [Line Items] |  |
Revenues | 11 | 13
Operating income (loss) | 3 | 2
Other Utility [Member] | IPL [Member] |  |
Segment Reporting Information [Line Items] |  |
Revenues | 11 | 12
Operating income (loss) | 3 | 1
Other Utility [Member] | WPL [Member] |  |
Segment Reporting Information [Line Items] |  |
Revenues | 0 | 1
Operating income (loss) | 0 | 1
Utility Business [Member] |  |
Segment Reporting Information [Line Items] |  |
Revenues | 1,046 | 884
Operating income (loss) | 241 | 193
Net income attributable to common shareowners | 179 | 163
ATC Holdings, Non-Utility, Parent and Other [Member] |  |
Segment Reporting Information [Line Items] |  |
Revenues | 22 | 17
Operating income (loss) | 7 | 5
Net income attributable to common shareowners | $ 13 | $ 8

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