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v3.21.2

Segments Of Business (Schedule Of Segments Of Business) (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020
Segment Reporting Information [Line Items] |  |  |  |
Revenues | $ 817 | $ 763 | $ 1,718 | $ 1,679
Operating income (loss) | 176 | 168 | 374 | 356
Net income attributable to common shareowners | 144 | 134 | 315 | 304
Net income | 146 | 136 | 320 | 309
IPL [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenues | 455 | 432 | 944 | 951
Operating income (loss) | 111 | 88 | 214 | 185
Net income attributable to common shareowners | 86 | 60 | 165 | 142
Net income | 88 | 62 | 170 | 147
WPL [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenues | 341 | 312 | 736 | 687
Operating income (loss) | 55 | 72 | 145 | 166
Net income | 38 | 58 | 122 | 147
Electric [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenues | 717 | 675 | 1,418 | 1,405
Operating income (loss) | 164 | 152 | 311 | 298
Electric [Member] | IPL [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenues | 402 | 388 | 788 | 813
Operating income (loss) | 107 | 82 | 179 | 149
Electric [Member] | WPL [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenues | 315 | 287 | 630 | 592
Operating income (loss) | 57 | 70 | 132 | 149
Gas [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenues | 69 | 59 | 239 | 211
Operating income (loss) | 3 | 7 | 47 | 49
Gas [Member] | IPL [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenues | 43 | 34 | 134 | 117
Operating income (loss) | 3 | 5 | 33 | 33
Gas [Member] | WPL [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenues | 26 | 25 | 105 | 94
Operating income (loss) | 0 | 2 | 14 | 16
Other Utility [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenues | 10 | 10 | 23 | 22
Operating income (loss) | (1) | 1 | 1 | 4
Other Utility [Member] | IPL [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenues | 10 | 10 | 22 | 21
Operating income (loss) | 1 | 1 | 2 | 3
Other Utility [Member] | WPL [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenues | 0 | 0 | 1 | 1
Operating income (loss) | (2) | 0 | (1) | 1
Utility Business [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenues | 796 | 744 | 1,680 | 1,638
Operating income (loss) | 166 | 160 | 359 | 351
Net income attributable to common shareowners | 124 | 118 | 287 | 289
Non-Utility [Member] | ATC Holdings, Non-Utility, Parent and Other [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenues | 21 | 19 | 38 | 41
Operating income (loss) | 10 | 8 | 15 | 5
Net income attributable to common shareowners | $ 20 | $ 16 | $ 28 | $ 15

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