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v3.22.2.2

Summary Of Significant Accounting Policies (Narrative) (Details) $ in Millions | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Sep. 30, 2022 USD ($) | Jun. 30, 2022 USD ($) | Sep. 30, 2022 USD ($) | Sep. 30, 2021 USD ($) | Dec. 31, 2024 MW | Dec. 31, 2021 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |
Money market fund investments | $ 334 |  | $ 334 |  |  | $ 32
Money market fund investments interest rate, percentage | 3.00% |  | 3.00% |  |  |
Distributions to noncontrolling interest |  |  | $ 29 | $ 0 |  |
IPL [Member] |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |
Money market fund investments | $ 39 |  | $ 39 |  |  | 32
Money market fund investments interest rate, percentage | 3.00% |  | 3.00% |  |  |
WPL [Member] |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |
Money market fund investments | $ 295 |  | $ 295 |  |  | $ 0
Money market fund investments interest rate, percentage | 3.00% |  | 3.00% |  |  |
WPL's cash contribution |  | $ 62 |  |  |  |
Tax equity partner's cash contribution |  | 29 |  |  |  |
Contributed funds paid to WPL for equity interests |  | $ 88 |  |  |  |
Distributions to noncontrolling interest | $ 29 |  | $ 29 | $ 0 |  |
WPL [Member] | Solar [Member] | Forecast [Member] |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |
Nameplate capacity (in MW) | MW |  |  |  |  | 1,100 |

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