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Segments Of Business | 3 Months Ended
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Mar. 31, 2024
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 March 31, 2024 |  |  |  |  |  |  |  |  |  |  |
Revenues | $791 |  | $205 |  | $13 |  | $1,009 |  | $22 |  | $1,031
Operating income | 164 |  | 47 |  | 5 |  | 216 |  | 6 |  | 222
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 155 |  | 3 |  | 158
Three Months Ended March 31, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $768 |  | $276 |  | $11 |  | $1,055 |  | $22 |  | $1,077
Operating income | 163 |  | 50 |  | 4 |  | 217 |  | 5 |  | 222
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 160 |  | 3 |  | 163
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2024 |  |  |  |  |  |  |
Revenues | $392 |  | $108 |  | $13 |  | $513
Operating income | 57 |  | 22 |  | 6 |  | 85
Net income |  |  |  |  |  |  | 63
Three Months Ended March 31, 2023 |  |  |  |  |  |  |
Revenues | $388 |  | $150 |  | $11 |  | $549
Operating income | 66 |  | 27 |  | 3 |  | 96
Net income |  |  |  |  |  |  | 72
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2024 |  |  |  |  |  |  |
Revenues | $399 |  | $97 |  | $— |  | $496
Operating income (loss) | 107 |  | 25 |  | (1) |  | 131
Net income |  |  |  |  |  |  | 92
Three Months Ended March 31, 2023 |  |  |  |  |  |  |
Revenues | $380 |  | $126 |  | $— |  | $506
Operating income | 97 |  | 23 |  | 1 |  | 121
Net income |  |  |  |  |  |  | 88
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 March 31, 2024 |  |  |  |  |  |  |  |  |  |  |
Revenues | $791 |  | $205 |  | $13 |  | $1,009 |  | $22 |  | $1,031
Operating income | 164 |  | 47 |  | 5 |  | 216 |  | 6 |  | 222
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 155 |  | 3 |  | 158
Three Months Ended March 31, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $768 |  | $276 |  | $11 |  | $1,055 |  | $22 |  | $1,077
Operating income | 163 |  | 50 |  | 4 |  | 217 |  | 5 |  | 222
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 160 |  | 3 |  | 163
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2024 |  |  |  |  |  |  |
Revenues | $392 |  | $108 |  | $13 |  | $513
Operating income | 57 |  | 22 |  | 6 |  | 85
Net income |  |  |  |  |  |  | 63
Three Months Ended March 31, 2023 |  |  |  |  |  |  |
Revenues | $388 |  | $150 |  | $11 |  | $549
Operating income | 66 |  | 27 |  | 3 |  | 96
Net income |  |  |  |  |  |  | 72
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2024 |  |  |  |  |  |  |
Revenues | $399 |  | $97 |  | $— |  | $496
Operating income (loss) | 107 |  | 25 |  | (1) |  | 131
Net income |  |  |  |  |  |  | 92
Three Months Ended March 31, 2023 |  |  |  |  |  |  |
Revenues | $380 |  | $126 |  | $— |  | $506
Operating income | 97 |  | 23 |  | 1 |  | 121
Net income |  |  |  |  |  |  | 88
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 March 31, 2024 |  |  |  |  |  |  |  |  |  |  |
Revenues | $791 |  | $205 |  | $13 |  | $1,009 |  | $22 |  | $1,031
Operating income | 164 |  | 47 |  | 5 |  | 216 |  | 6 |  | 222
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 155 |  | 3 |  | 158
Three Months Ended March 31, 2023 |  |  |  |  |  |  |  |  |  |  |
Revenues | $768 |  | $276 |  | $11 |  | $1,055 |  | $22 |  | $1,077
Operating income | 163 |  | 50 |  | 4 |  | 217 |  | 5 |  | 222
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 160 |  | 3 |  | 163
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2024 |  |  |  |  |  |  |
Revenues | $392 |  | $108 |  | $13 |  | $513
Operating income | 57 |  | 22 |  | 6 |  | 85
Net income |  |  |  |  |  |  | 63
Three Months Ended March 31, 2023 |  |  |  |  |  |  |
Revenues | $388 |  | $150 |  | $11 |  | $549
Operating income | 66 |  | 27 |  | 3 |  | 96
Net income |  |  |  |  |  |  | 72
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2024 |  |  |  |  |  |  |
Revenues | $399 |  | $97 |  | $— |  | $496
Operating income (loss) | 107 |  | 25 |  | (1) |  | 131
Net income |  |  |  |  |  |  | 92
Three Months Ended March 31, 2023 |  |  |  |  |  |  |
Revenues | $380 |  | $126 |  | $— |  | $506
Operating income | 97 |  | 23 |  | 1 |  | 121
Net income |  |  |  |  |  |  | 88

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