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Segments Of Business (Tables) | 9 Months Ended
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Sep. 30, 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 September 30, 2021 |  |  |  |  |  |  |  |  |  |  |
Revenues | $939 |  | $50 |  | $13 |  | $1,002 |  | $22 |  | $1,024
Operating income (loss) | 290 |  | (5) |  | (5) |  | 280 |  | 9 |  | 289
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 250 |  | 6 |  | 256
Three Months Ended September 30, 2020 |  |  |  |  |  |  |  |  |  |  |
Revenues | $852 |  | $42 |  | $10 |  | $904 |  | $16 |  | $920
Operating income (loss) | 251 |  | (1) |  | 1 |  | 251 |  | 21 |  | 272
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 221 |  | 25 |  | 246
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,357 |  | $289 |  | $36 |  | $2,682 |  | $60 |  | $2,742
Operating income (loss) | 601 |  | 42 |  | (4) |  | 639 |  | 24 |  | 663
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 537 |  | 34 |  | 571
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,257 |  | $253 |  | $32 |  | $2,542 |  | $57 |  | $2,599
Operating income | 549 |  | 48 |  | 5 |  | 602 |  | 26 |  | 628
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 510 |  | 40 |  | 550
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $555 |  | $31 |  | $13 |  | $599
Operating income (loss) | 186 |  | (3) |  | (3) |  | 180
Net income available for common stock |  |  |  |  |  |  | 157
Three Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $519 |  | $24 |  | $10 |  | $553
Operating income | 159 |  | 1 |  | 2 |  | 162
Net income available for common stock |  |  |  |  |  |  | 148
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $1,343 |  | $165 |  | $35 |  | $1,543
Operating income (loss) | 365 |  | 30 |  | (1) |  | 394
Net income available for common stock |  |  |  |  |  |  | 322
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $1,332 |  | $141 |  | $31 |  | $1,504
Operating income | 308 |  | 34 |  | 5 |  | 347
Net income available for common stock |  |  |  |  |  |  | 290
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $384 |  | $19 |  | $— |  | $403
Operating income (loss) | 104 |  | (2) |  | (2) |  | 100
Net income |  |  |  |  |  |  | 93
Three Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $333 |  | $18 |  | $— |  | $351
Operating income (loss) | 92 |  | (2) |  | (1) |  | 89
Net income |  |  |  |  |  |  | 73
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $1,014 |  | $124 |  | $1 |  | $1,139
Operating income (loss) | 236 |  | 12 |  | (3) |  | 245
Net income |  |  |  |  |  |  | 215
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $925 |  | $112 |  | $1 |  | $1,038
Operating income | 241 |  | 14 |  | — |  | 255
Net income |  |  |  |  |  |  | 220
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 September 30, 2021 |  |  |  |  |  |  |  |  |  |  |
Revenues | $939 |  | $50 |  | $13 |  | $1,002 |  | $22 |  | $1,024
Operating income (loss) | 290 |  | (5) |  | (5) |  | 280 |  | 9 |  | 289
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 250 |  | 6 |  | 256
Three Months Ended September 30, 2020 |  |  |  |  |  |  |  |  |  |  |
Revenues | $852 |  | $42 |  | $10 |  | $904 |  | $16 |  | $920
Operating income (loss) | 251 |  | (1) |  | 1 |  | 251 |  | 21 |  | 272
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 221 |  | 25 |  | 246
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,357 |  | $289 |  | $36 |  | $2,682 |  | $60 |  | $2,742
Operating income (loss) | 601 |  | 42 |  | (4) |  | 639 |  | 24 |  | 663
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 537 |  | 34 |  | 571
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,257 |  | $253 |  | $32 |  | $2,542 |  | $57 |  | $2,599
Operating income | 549 |  | 48 |  | 5 |  | 602 |  | 26 |  | 628
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 510 |  | 40 |  | 550
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $555 |  | $31 |  | $13 |  | $599
Operating income (loss) | 186 |  | (3) |  | (3) |  | 180
Net income available for common stock |  |  |  |  |  |  | 157
Three Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $519 |  | $24 |  | $10 |  | $553
Operating income | 159 |  | 1 |  | 2 |  | 162
Net income available for common stock |  |  |  |  |  |  | 148
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $1,343 |  | $165 |  | $35 |  | $1,543
Operating income (loss) | 365 |  | 30 |  | (1) |  | 394
Net income available for common stock |  |  |  |  |  |  | 322
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $1,332 |  | $141 |  | $31 |  | $1,504
Operating income | 308 |  | 34 |  | 5 |  | 347
Net income available for common stock |  |  |  |  |  |  | 290
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $384 |  | $19 |  | $— |  | $403
Operating income (loss) | 104 |  | (2) |  | (2) |  | 100
Net income |  |  |  |  |  |  | 93
Three Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $333 |  | $18 |  | $— |  | $351
Operating income (loss) | 92 |  | (2) |  | (1) |  | 89
Net income |  |  |  |  |  |  | 73
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $1,014 |  | $124 |  | $1 |  | $1,139
Operating income (loss) | 236 |  | 12 |  | (3) |  | 245
Net income |  |  |  |  |  |  | 215
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $925 |  | $112 |  | $1 |  | $1,038
Operating income | 241 |  | 14 |  | — |  | 255
Net income |  |  |  |  |  |  | 220
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 September 30, 2021 |  |  |  |  |  |  |  |  |  |  |
Revenues | $939 |  | $50 |  | $13 |  | $1,002 |  | $22 |  | $1,024
Operating income (loss) | 290 |  | (5) |  | (5) |  | 280 |  | 9 |  | 289
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 250 |  | 6 |  | 256
Three Months Ended September 30, 2020 |  |  |  |  |  |  |  |  |  |  |
Revenues | $852 |  | $42 |  | $10 |  | $904 |  | $16 |  | $920
Operating income (loss) | 251 |  | (1) |  | 1 |  | 251 |  | 21 |  | 272
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 221 |  | 25 |  | 246
Alliant Energy |  |  |  |  |  |  |  |  | ATC Holdings, |  | Alliant
| Utility |  | Non-Utility, |  | Energy
| Electric |  | Gas |  | Other |  | Total |  | Parent and Other |  | Consolidated
| (in millions)
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,357 |  | $289 |  | $36 |  | $2,682 |  | $60 |  | $2,742
Operating income (loss) | 601 |  | 42 |  | (4) |  | 639 |  | 24 |  | 663
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 537 |  | 34 |  | 571
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |  |  |  |  |
Revenues | $2,257 |  | $253 |  | $32 |  | $2,542 |  | $57 |  | $2,599
Operating income | 549 |  | 48 |  | 5 |  | 602 |  | 26 |  | 628
Net income attributable to Alliant Energy common shareowners |  |  |  |  |  |  | 510 |  | 40 |  | 550
IPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $555 |  | $31 |  | $13 |  | $599
Operating income (loss) | 186 |  | (3) |  | (3) |  | 180
Net income available for common stock |  |  |  |  |  |  | 157
Three Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $519 |  | $24 |  | $10 |  | $553
Operating income | 159 |  | 1 |  | 2 |  | 162
Net income available for common stock |  |  |  |  |  |  | 148
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $1,343 |  | $165 |  | $35 |  | $1,543
Operating income (loss) | 365 |  | 30 |  | (1) |  | 394
Net income available for common stock |  |  |  |  |  |  | 322
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $1,332 |  | $141 |  | $31 |  | $1,504
Operating income | 308 |  | 34 |  | 5 |  | 347
Net income available for common stock |  |  |  |  |  |  | 290
WPL | Electric |  | Gas |  | Other |  | Total
| (in millions)
Three Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $384 |  | $19 |  | $— |  | $403
Operating income (loss) | 104 |  | (2) |  | (2) |  | 100
Net income |  |  |  |  |  |  | 93
Three Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $333 |  | $18 |  | $— |  | $351
Operating income (loss) | 92 |  | (2) |  | (1) |  | 89
Net income |  |  |  |  |  |  | 73
Nine Months Ended September 30, 2021 |  |  |  |  |  |  |
Revenues | $1,014 |  | $124 |  | $1 |  | $1,139
Operating income (loss) | 236 |  | 12 |  | (3) |  | 245
Net income |  |  |  |  |  |  | 215
Nine Months Ended September 30, 2020 |  |  |  |  |  |  |
Revenues | $925 |  | $112 |  | $1 |  | $1,038
Operating income | 241 |  | 14 |  | — |  | 255
Net income |  |  |  |  |  |  | 220

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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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