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Segments Of Business | 9 Months Ended
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Sep. 30, 2023
Segment Reporting Information [Line Items] |
Segments Of Business | SEGMENTS OF BUSINESS Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations.
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Three Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $995 |  | $47 |  | $13 |  | $1,055 |  | $22 |  | $1,077
Operating income (loss) | 319 |  | (4) |  | — |  | 315 |  | 7 |  | 322
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 277 |  | (18) |  | 259
Three Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |  |  |
Revenues | $1,039 |  | $62 |  | $11 |  | $1,112 |  | $23 |  | $1,135
Operating income (loss) | 304 |  | (3) |  | 1 |  | 302 |  | 7 |  | 309
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 245 |  | (18) |  | 227
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,562 |  | $400 |  | $38 |  | $3,000 |  | $66 |  | $3,066
Operating income | 682 |  | 48 |  | 12 |  | 742 |  | 18 |  | 760
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 598 |  | (16) |  | 582
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,624 |  | $418 |  | $35 |  | $3,077 |  | $70 |  | $3,147
Operating income | 680 |  | 62 |  | 4 |  | 746 |  | 23 |  | 769
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 574 |  | 5 |  | 579
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $551 |  | $31 |  | $12 |  | $594
Operating income (loss) | 171 |  | (2) |  | 4 |  | 173
Net income |  |  |  |  |  |  | 170
Three Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $596 |  | $33 |  | $11 |  | $640
Operating income (loss) | 174 |  | (3) |  | — |  | 171
Net income |  |  |  |  |  |  | 154
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $1,370 |  | $224 |  | $36 |  | $1,630
Operating income | 342 |  | 25 |  | 12 |  | 379
Net income |  |  |  |  |  |  | 331
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $1,438 |  | $224 |  | $34 |  | $1,696
Operating income | 353 |  | 33 |  | 3 |  | 389
Net income |  |  |  |  |  |  | 327
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $444 |  | $16 |  | $1 |  | $461
Operating income (loss) | 148 |  | (2) |  | (4) |  | 142
Net income |  |  |  |  |  |  | 107
Three Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $443 |  | $29 |  | $— |  | $472
Operating income | 130 |  | — |  | 1 |  | 131
Net income |  |  |  |  |  |  | 91
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $1,192 |  | $176 |  | $2 |  | $1,370
Operating income | 340 |  | 23 |  | — |  | 363
Net income |  |  |  |  |  |  | 267
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $1,186 |  | $194 |  | $1 |  | $1,381
Operating income | 327 |  | 29 |  | 1 |  | 357
Net income |  |  |  |  |  |  | 247
IPL [Member] |
Segment Reporting Information [Line Items] |
Segments Of Business | SEGMENTS OF BUSINESS Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations.
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Three Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $995 |  | $47 |  | $13 |  | $1,055 |  | $22 |  | $1,077
Operating income (loss) | 319 |  | (4) |  | — |  | 315 |  | 7 |  | 322
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 277 |  | (18) |  | 259
Three Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |  |  |
Revenues | $1,039 |  | $62 |  | $11 |  | $1,112 |  | $23 |  | $1,135
Operating income (loss) | 304 |  | (3) |  | 1 |  | 302 |  | 7 |  | 309
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 245 |  | (18) |  | 227
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,562 |  | $400 |  | $38 |  | $3,000 |  | $66 |  | $3,066
Operating income | 682 |  | 48 |  | 12 |  | 742 |  | 18 |  | 760
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 598 |  | (16) |  | 582
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,624 |  | $418 |  | $35 |  | $3,077 |  | $70 |  | $3,147
Operating income | 680 |  | 62 |  | 4 |  | 746 |  | 23 |  | 769
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 574 |  | 5 |  | 579
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $551 |  | $31 |  | $12 |  | $594
Operating income (loss) | 171 |  | (2) |  | 4 |  | 173
Net income |  |  |  |  |  |  | 170
Three Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $596 |  | $33 |  | $11 |  | $640
Operating income (loss) | 174 |  | (3) |  | — |  | 171
Net income |  |  |  |  |  |  | 154
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $1,370 |  | $224 |  | $36 |  | $1,630
Operating income | 342 |  | 25 |  | 12 |  | 379
Net income |  |  |  |  |  |  | 331
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $1,438 |  | $224 |  | $34 |  | $1,696
Operating income | 353 |  | 33 |  | 3 |  | 389
Net income |  |  |  |  |  |  | 327
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $444 |  | $16 |  | $1 |  | $461
Operating income (loss) | 148 |  | (2) |  | (4) |  | 142
Net income |  |  |  |  |  |  | 107
Three Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $443 |  | $29 |  | $— |  | $472
Operating income | 130 |  | — |  | 1 |  | 131
Net income |  |  |  |  |  |  | 91
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $1,192 |  | $176 |  | $2 |  | $1,370
Operating income | 340 |  | 23 |  | — |  | 363
Net income |  |  |  |  |  |  | 267
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $1,186 |  | $194 |  | $1 |  | $1,381
Operating income | 327 |  | 29 |  | 1 |  | 357
Net income |  |  |  |  |  |  | 247
WPL [Member] |
Segment Reporting Information [Line Items] |
Segments Of Business | SEGMENTS OF BUSINESS Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations.
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Three Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $995 |  | $47 |  | $13 |  | $1,055 |  | $22 |  | $1,077
Operating income (loss) | 319 |  | (4) |  | — |  | 315 |  | 7 |  | 322
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 277 |  | (18) |  | 259
Three Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |  |  |
Revenues | $1,039 |  | $62 |  | $11 |  | $1,112 |  | $23 |  | $1,135
Operating income (loss) | 304 |  | (3) |  | 1 |  | 302 |  | 7 |  | 309
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 245 |  | (18) |  | 227
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,562 |  | $400 |  | $38 |  | $3,000 |  | $66 |  | $3,066
Operating income | 682 |  | 48 |  | 12 |  | 742 |  | 18 |  | 760
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 598 |  | (16) |  | 582
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,624 |  | $418 |  | $35 |  | $3,077 |  | $70 |  | $3,147
Operating income | 680 |  | 62 |  | 4 |  | 746 |  | 23 |  | 769
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 574 |  | 5 |  | 579
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $551 |  | $31 |  | $12 |  | $594
Operating income (loss) | 171 |  | (2) |  | 4 |  | 173
Net income |  |  |  |  |  |  | 170
Three Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $596 |  | $33 |  | $11 |  | $640
Operating income (loss) | 174 |  | (3) |  | — |  | 171
Net income |  |  |  |  |  |  | 154
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $1,370 |  | $224 |  | $36 |  | $1,630
Operating income | 342 |  | 25 |  | 12 |  | 379
Net income |  |  |  |  |  |  | 331
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $1,438 |  | $224 |  | $34 |  | $1,696
Operating income | 353 |  | 33 |  | 3 |  | 389
Net income |  |  |  |  |  |  | 327
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $444 |  | $16 |  | $1 |  | $461
Operating income (loss) | 148 |  | (2) |  | (4) |  | 142
Net income |  |  |  |  |  |  | 107
Three Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $443 |  | $29 |  | $— |  | $472
Operating income | 130 |  | — |  | 1 |  | 131
Net income |  |  |  |  |  |  | 91
Nine Months Ended September 30, 2023 |  |  |  |  |  |  |
Revenues | $1,192 |  | $176 |  | $2 |  | $1,370
Operating income | 340 |  | 23 |  | — |  | 363
Net income |  |  |  |  |  |  | 267
Nine Months Ended September 30, 2022 |  |  |  |  |  |  |
Revenues | $1,186 |  | $194 |  | $1 |  | $1,381
Operating income | 327 |  | 29 |  | 1 |  | 357
Net income |  |  |  |  |  |  | 247

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