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Commitments And Contingencies (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2020 | Dec. 31, 2019
Long-term Purchase Commitment [Line Items] |  |  |  |  |
Equity income from unconsolidated investments, net | $ (61) | $ (61) | $ (51) |  |
Whiting Petroleum Corporation |  |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |  |
Partnership share, percent | 6.00% |  |  |  |
Obligations, maximum | $ 54 |  |  |  |
Capital Purchase Commitment [Member] |  |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |  |
Minimum future commitments | $ 448 |  |  |  |
IPL [Member] |  |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |  |
Base return on equity, percentage | 10.25% |  |  |  |
IPL [Member] | Capital Purchase Commitment [Member] |  |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |  |
Minimum future commitments | $ 294 |  |  |  |
WPL [Member] | Capital Purchase Commitment [Member] |  |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |  |
Minimum future commitments | 153 |  |  |  |
Indemnification Agreement [Member] |  |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |  |
Obligations, maximum | 43 |  |  |  |
Indemnification Agreement [Member] | Purchased Power [Member] |  |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |  |
Obligations, maximum | 17 |  |  |  |
Indemnification Agreement [Member] | IPL [Member] | Renewable Tax Credits Transferred [Member] |  |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |  |
Obligations, maximum | 193 |  |  |  |
Indemnification Agreement [Member] | WPL [Member] | Renewable Tax Credits Transferred [Member] |  |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |  |
Obligations, maximum | $ 121 |  |  |  |
FERC [Member] |  |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |  |
Base return on equity, percentage | 9.98% |  |  | 10.02% | 9.88%
Equity income from unconsolidated investments, net |  |  | $ 6 |  |

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