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Segments Of Business (Tables) | 3 Months Ended
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Mar. 31, 2021
Segment Reporting Information [Line Items] |
Schedule Of 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, 2021 |  |  |  |  |  |  |  |  |  |  |
Revenues | $701 |  | $170 |  | $13 |  | $884 |  | $17 |  | $901
Operating income | 147 |  | 44 |  | 2 |  | 193 |  | 5 |  | 198
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 163 |  | 8 |  | 171
Three Months Ended March 31, 2020 |  |  |  |  |  |  |  |  |  |  |
Revenues | $730 |  | $152 |  | $12 |  | $894 |  | $22 |  | $916
Operating income (loss) | 146 |  | 41 |  | 4 |  | 191 |  | (3) |  | 188
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 173 |  | (3) |  | 170
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2021 |  |  |  |  |  |  |
Revenues | $386 |  | $91 |  | $12 |  | $489
Operating income | 72 |  | 30 |  | 1 |  | 103
Net income available for common stock |  |  |  |  |  |  | 79
Three Months Ended March 31, 2020 |  |  |  |  |  |  |
Revenues | $425 |  | $83 |  | $11 |  | $519
Operating income | 67 |  | 27 |  | 3 |  | 97
Net income available for common stock |  |  |  |  |  |  | 83
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2021 |  |  |  |  |  |  |
Revenues | $315 |  | $79 |  | $1 |  | $395
Operating income | 75 |  | 14 |  | 1 |  | 90
Net income |  |  |  |  |  |  | 84
Three Months Ended March 31, 2020 |  |  |  |  |  |  |
Revenues | $305 |  | $69 |  | $1 |  | $375
Operating income | 79 |  | 14 |  | 1 |  | 94
Net income |  |  |  |  |  |  | 90
IPL [Member] |
Segment Reporting Information [Line Items] |
Schedule Of 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, 2021 |  |  |  |  |  |  |  |  |  |  |
Revenues | $701 |  | $170 |  | $13 |  | $884 |  | $17 |  | $901
Operating income | 147 |  | 44 |  | 2 |  | 193 |  | 5 |  | 198
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 163 |  | 8 |  | 171
Three Months Ended March 31, 2020 |  |  |  |  |  |  |  |  |  |  |
Revenues | $730 |  | $152 |  | $12 |  | $894 |  | $22 |  | $916
Operating income (loss) | 146 |  | 41 |  | 4 |  | 191 |  | (3) |  | 188
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 173 |  | (3) |  | 170
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2021 |  |  |  |  |  |  |
Revenues | $386 |  | $91 |  | $12 |  | $489
Operating income | 72 |  | 30 |  | 1 |  | 103
Net income available for common stock |  |  |  |  |  |  | 79
Three Months Ended March 31, 2020 |  |  |  |  |  |  |
Revenues | $425 |  | $83 |  | $11 |  | $519
Operating income | 67 |  | 27 |  | 3 |  | 97
Net income available for common stock |  |  |  |  |  |  | 83
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2021 |  |  |  |  |  |  |
Revenues | $315 |  | $79 |  | $1 |  | $395
Operating income | 75 |  | 14 |  | 1 |  | 90
Net income |  |  |  |  |  |  | 84
Three Months Ended March 31, 2020 |  |  |  |  |  |  |
Revenues | $305 |  | $69 |  | $1 |  | $375
Operating income | 79 |  | 14 |  | 1 |  | 94
Net income |  |  |  |  |  |  | 90
WPL [Member] |
Segment Reporting Information [Line Items] |
Schedule Of 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, 2021 |  |  |  |  |  |  |  |  |  |  |
Revenues | $701 |  | $170 |  | $13 |  | $884 |  | $17 |  | $901
Operating income | 147 |  | 44 |  | 2 |  | 193 |  | 5 |  | 198
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 163 |  | 8 |  | 171
Three Months Ended March 31, 2020 |  |  |  |  |  |  |  |  |  |  |
Revenues | $730 |  | $152 |  | $12 |  | $894 |  | $22 |  | $916
Operating income (loss) | 146 |  | 41 |  | 4 |  | 191 |  | (3) |  | 188
Net income (loss) attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 173 |  | (3) |  | 170
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2021 |  |  |  |  |  |  |
Revenues | $386 |  | $91 |  | $12 |  | $489
Operating income | 72 |  | 30 |  | 1 |  | 103
Net income available for common stock |  |  |  |  |  |  | 79
Three Months Ended March 31, 2020 |  |  |  |  |  |  |
Revenues | $425 |  | $83 |  | $11 |  | $519
Operating income | 67 |  | 27 |  | 3 |  | 97
Net income available for common stock |  |  |  |  |  |  | 83
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended March 31, 2021 |  |  |  |  |  |  |
Revenues | $315 |  | $79 |  | $1 |  | $395
Operating income | 75 |  | 14 |  | 1 |  | 90
Net income |  |  |  |  |  |  | 84
Three Months Ended March 31, 2020 |  |  |  |  |  |  |
Revenues | $305 |  | $69 |  | $1 |  | $375
Operating income | 79 |  | 14 |  | 1 |  | 94
Net income |  |  |  |  |  |  | 90

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- Definition Tabular disclosure of the profit or loss and total assets for each reportable segment. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 25 -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8813-108599 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599 + Details
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