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Revenues (Tables) | 9 Months Ended
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Sep. 30, 2021
Disaggregation of Revenue [Line Items] |
Disaggregation of Revenue | Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Three Months Ended September 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $348 |  | $328 |  | $207 |  | $189 |  | $141 |  | $139
Retail - commercial | 232 |  | 210 |  | 160 |  | 142 |  | 72 |  | 68
Retail - industrial | 265 |  | 241 |  | 158 |  | 149 |  | 107 |  | 92
Wholesale | 55 |  | 47 |  | 18 |  | 17 |  | 37 |  | 30
Bulk power and other | 39 |  | 26 |  | 12 |  | 22 |  | 27 |  | 4
Total Electric Utility | 939 |  | 852 |  | 555 |  | 519 |  | 384 |  | 333
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 24 |  | 22 |  | 14 |  | 12 |  | 10 |  | 10
Retail - commercial | 13 |  | 10 |  | 8 |  | 6 |  | 5 |  | 4
Retail - industrial | 3 |  | 2 |  | 3 |  | 1 |  | — |  | 1
Transportation/other | 10 |  | 8 |  | 6 |  | 5 |  | 4 |  | 3
Total Gas Utility | 50 |  | 42 |  | 31 |  | 24 |  | 19 |  | 18
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 9 |  | 8 |  | 9 |  | 8 |  | — |  | —
Other utility | 4 |  | 2 |  | 4 |  | 2 |  | — |  | —
Total Other Utility | 13 |  | 10 |  | 13 |  | 10 |  | — |  | —
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 22 |  | 16 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 22 |  | 16 |  | — |  | — |  | — |  | —
Total revenues | $1,024 |  | $920 |  | $599 |  | $553 |  | $403 |  | $351
| Alliant Energy |  | IPL |  | WPL
Nine Months Ended September 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $868 |  | $845 |  | $488 |  | $472 |  | $380 |  | $373
Retail - commercial | 579 |  | 556 |  | 385 |  | 371 |  | 194 |  | 185
Retail - industrial | 677 |  | 648 |  | 386 |  | 384 |  | 291 |  | 264
Wholesale | 142 |  | 127 |  | 44 |  | 44 |  | 98 |  | 83
Bulk power and other | 91 |  | 81 |  | 40 |  | 61 |  | 51 |  | 20
Total Electric Utility | 2,357 |  | 2,257 |  | 1,343 |  | 1,332 |  | 1,014 |  | 925
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 162 |  | 146 |  | 90 |  | 79 |  | 72 |  | 67
Retail - commercial | 85 |  | 70 |  | 47 |  | 38 |  | 38 |  | 32
Retail - industrial | 11 |  | 8 |  | 8 |  | 5 |  | 3 |  | 3
Transportation/other | 31 |  | 29 |  | 20 |  | 19 |  | 11 |  | 10
Total Gas Utility | 289 |  | 253 |  | 165 |  | 141 |  | 124 |  | 112
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 27 |  | 27 |  | 27 |  | 27 |  | — |  | —
Other utility | 9 |  | 5 |  | 8 |  | 4 |  | 1 |  | 1
Total Other Utility | 36 |  | 32 |  | 35 |  | 31 |  | 1 |  | 1
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 60 |  | 57 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 60 |  | 57 |  | — |  | — |  | — |  | —
Total revenues | $2,742 |  | $2,599 |  | $1,543 |  | $1,504 |  | $1,139 |  | $1,038
IPL [Member] |
Disaggregation of Revenue [Line Items] |
Disaggregation of Revenue | Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Three Months Ended September 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $348 |  | $328 |  | $207 |  | $189 |  | $141 |  | $139
Retail - commercial | 232 |  | 210 |  | 160 |  | 142 |  | 72 |  | 68
Retail - industrial | 265 |  | 241 |  | 158 |  | 149 |  | 107 |  | 92
Wholesale | 55 |  | 47 |  | 18 |  | 17 |  | 37 |  | 30
Bulk power and other | 39 |  | 26 |  | 12 |  | 22 |  | 27 |  | 4
Total Electric Utility | 939 |  | 852 |  | 555 |  | 519 |  | 384 |  | 333
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 24 |  | 22 |  | 14 |  | 12 |  | 10 |  | 10
Retail - commercial | 13 |  | 10 |  | 8 |  | 6 |  | 5 |  | 4
Retail - industrial | 3 |  | 2 |  | 3 |  | 1 |  | — |  | 1
Transportation/other | 10 |  | 8 |  | 6 |  | 5 |  | 4 |  | 3
Total Gas Utility | 50 |  | 42 |  | 31 |  | 24 |  | 19 |  | 18
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 9 |  | 8 |  | 9 |  | 8 |  | — |  | —
Other utility | 4 |  | 2 |  | 4 |  | 2 |  | — |  | —
Total Other Utility | 13 |  | 10 |  | 13 |  | 10 |  | — |  | —
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 22 |  | 16 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 22 |  | 16 |  | — |  | — |  | — |  | —
Total revenues | $1,024 |  | $920 |  | $599 |  | $553 |  | $403 |  | $351
| Alliant Energy |  | IPL |  | WPL
Nine Months Ended September 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $868 |  | $845 |  | $488 |  | $472 |  | $380 |  | $373
Retail - commercial | 579 |  | 556 |  | 385 |  | 371 |  | 194 |  | 185
Retail - industrial | 677 |  | 648 |  | 386 |  | 384 |  | 291 |  | 264
Wholesale | 142 |  | 127 |  | 44 |  | 44 |  | 98 |  | 83
Bulk power and other | 91 |  | 81 |  | 40 |  | 61 |  | 51 |  | 20
Total Electric Utility | 2,357 |  | 2,257 |  | 1,343 |  | 1,332 |  | 1,014 |  | 925
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 162 |  | 146 |  | 90 |  | 79 |  | 72 |  | 67
Retail - commercial | 85 |  | 70 |  | 47 |  | 38 |  | 38 |  | 32
Retail - industrial | 11 |  | 8 |  | 8 |  | 5 |  | 3 |  | 3
Transportation/other | 31 |  | 29 |  | 20 |  | 19 |  | 11 |  | 10
Total Gas Utility | 289 |  | 253 |  | 165 |  | 141 |  | 124 |  | 112
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 27 |  | 27 |  | 27 |  | 27 |  | — |  | —
Other utility | 9 |  | 5 |  | 8 |  | 4 |  | 1 |  | 1
Total Other Utility | 36 |  | 32 |  | 35 |  | 31 |  | 1 |  | 1
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 60 |  | 57 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 60 |  | 57 |  | — |  | — |  | — |  | —
Total revenues | $2,742 |  | $2,599 |  | $1,543 |  | $1,504 |  | $1,139 |  | $1,038
WPL [Member] |
Disaggregation of Revenue [Line Items] |
Disaggregation of Revenue | Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Three Months Ended September 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $348 |  | $328 |  | $207 |  | $189 |  | $141 |  | $139
Retail - commercial | 232 |  | 210 |  | 160 |  | 142 |  | 72 |  | 68
Retail - industrial | 265 |  | 241 |  | 158 |  | 149 |  | 107 |  | 92
Wholesale | 55 |  | 47 |  | 18 |  | 17 |  | 37 |  | 30
Bulk power and other | 39 |  | 26 |  | 12 |  | 22 |  | 27 |  | 4
Total Electric Utility | 939 |  | 852 |  | 555 |  | 519 |  | 384 |  | 333
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 24 |  | 22 |  | 14 |  | 12 |  | 10 |  | 10
Retail - commercial | 13 |  | 10 |  | 8 |  | 6 |  | 5 |  | 4
Retail - industrial | 3 |  | 2 |  | 3 |  | 1 |  | — |  | 1
Transportation/other | 10 |  | 8 |  | 6 |  | 5 |  | 4 |  | 3
Total Gas Utility | 50 |  | 42 |  | 31 |  | 24 |  | 19 |  | 18
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 9 |  | 8 |  | 9 |  | 8 |  | — |  | —
Other utility | 4 |  | 2 |  | 4 |  | 2 |  | — |  | —
Total Other Utility | 13 |  | 10 |  | 13 |  | 10 |  | — |  | —
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 22 |  | 16 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 22 |  | 16 |  | — |  | — |  | — |  | —
Total revenues | $1,024 |  | $920 |  | $599 |  | $553 |  | $403 |  | $351
| Alliant Energy |  | IPL |  | WPL
Nine Months Ended September 30 | 2021 |  | 2020 |  | 2021 |  | 2020 |  | 2021 |  | 2020
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $868 |  | $845 |  | $488 |  | $472 |  | $380 |  | $373
Retail - commercial | 579 |  | 556 |  | 385 |  | 371 |  | 194 |  | 185
Retail - industrial | 677 |  | 648 |  | 386 |  | 384 |  | 291 |  | 264
Wholesale | 142 |  | 127 |  | 44 |  | 44 |  | 98 |  | 83
Bulk power and other | 91 |  | 81 |  | 40 |  | 61 |  | 51 |  | 20
Total Electric Utility | 2,357 |  | 2,257 |  | 1,343 |  | 1,332 |  | 1,014 |  | 925
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 162 |  | 146 |  | 90 |  | 79 |  | 72 |  | 67
Retail - commercial | 85 |  | 70 |  | 47 |  | 38 |  | 38 |  | 32
Retail - industrial | 11 |  | 8 |  | 8 |  | 5 |  | 3 |  | 3
Transportation/other | 31 |  | 29 |  | 20 |  | 19 |  | 11 |  | 10
Total Gas Utility | 289 |  | 253 |  | 165 |  | 141 |  | 124 |  | 112
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 27 |  | 27 |  | 27 |  | 27 |  | — |  | —
Other utility | 9 |  | 5 |  | 8 |  | 4 |  | 1 |  | 1
Total Other Utility | 36 |  | 32 |  | 35 |  | 31 |  | 1 |  | 1
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 60 |  | 57 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 60 |  | 57 |  | — |  | — |  | — |  | —
Total revenues | $2,742 |  | $2,599 |  | $1,543 |  | $1,504 |  | $1,139 |  | $1,038

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