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Disaggregation of Revenues (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Disaggregation of Revenue [Line Items] |  |  |
Revenues | $ 3,669 | $ 3,416 | $ 3,648
IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 2,063 | 1,947 | 2,089
WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 1,523 | 1,395 | 1,476
Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 3,081 | 2,920 | 3,064
Electric [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 1,752 | 1,695 | 1,781
Electric [Member] | WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 1,329 | 1,225 | 1,283
Electric [Member] | Retail - Residential [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 1,115 | 1,093 | 1,092
Electric [Member] | Retail - Residential [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 620 | 602 | 601
Electric [Member] | Retail - Residential [Member] | WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 495 | 491 | 491
Electric [Member] | Retail - Commercial [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 763 | 718 | 770
Electric [Member] | Retail - Commercial [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 508 | 474 | 510
Electric [Member] | Retail - Commercial [Member] | WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 255 | 244 | 260
Electric [Member] | Retail - Industrial [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 893 | 841 | 889
Electric [Member] | Retail - Industrial [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 505 | 488 | 504
Electric [Member] | Retail - Industrial [Member] | WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 388 | 353 | 385
Electric [Member] | Wholesale [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 187 | 168 | 177
Electric [Member] | Wholesale [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 57 | 57 | 64
Electric [Member] | Wholesale [Member] | WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 130 | 111 | 113
Electric [Member] | Other [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 123 | 100 | 136
Electric [Member] | Other [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 62 | 74 | 102
Electric [Member] | Other [Member] | WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 61 | 26 | 34
Gas [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 456 | 373 | 455
Gas [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 265 | 208 | 264
Gas [Member] | WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 191 | 165 | 191
Gas [Member] | Retail - Residential [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 257 | 214 | 259
Gas [Member] | Retail - Residential [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 146 | 116 | 149
Gas [Member] | Retail - Residential [Member] | WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 111 | 98 | 110
Gas [Member] | Retail - Commercial [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 139 | 107 | 133
Gas [Member] | Retail - Commercial [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 79 | 59 | 75
Gas [Member] | Retail - Commercial [Member] | WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 60 | 48 | 58
Gas [Member] | Retail - Industrial [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 17 | 12 | 16
Gas [Member] | Retail - Industrial [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 12 | 8 | 12
Gas [Member] | Retail - Industrial [Member] | WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 5 | 4 | 4
Gas [Member] | Other [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 43 | 40 | 47
Gas [Member] | Other [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 28 | 25 | 28
Gas [Member] | Other [Member] | WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 15 | 15 | 19
Other Utility [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 49 | 49 | 46
Other Utility [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 46 | 44 | 44
Other Utility [Member] | WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 3 | 5 | 2
Other Utility [Member] | Other [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 13 | 13 | 9
Other Utility [Member] | Other [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 10 | 8 | 7
Other Utility [Member] | Other [Member] | WPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 3 | 5 | 2
Other Utility [Member] | Steam [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 36 | 36 | 37
Other Utility [Member] | Steam [Member] | IPL [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 36 | 36 | 37
Non-Utility and Other [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | 83 | 74 | 83
Non-Utility and Other [Member] | Other [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenues | $ 83 | $ 74 | $ 83

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