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Commitments And Contingencies (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Long-term Purchase Commitment [Line Items] |  |  |  |
Equity income from unconsolidated investments, net | $ 51 | $ 62 | $ 61 |
Whiting Petroleum Affiliate [Member] |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |
Partnership share, percent | 6.00% |  |  |
Obligations, maximum | $ 58 |  |  |
Credit loss liability | 5 |  |  |
Capital Purchase Commitment [Member] |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |
Minimum future commitments | 184 |  |  |
WPL [Member] | Capital Purchase Commitment [Member] |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |
Minimum future commitments | 180 |  |  |
Indemnification Agreement [Member] |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |
Obligations, maximum | 59 |  |  |
Indemnification Agreement [Member] | Purchased Power [Member] |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |
Obligations, maximum | 17 |  |  |
FERC [Member] |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |
Base return on equity, percentage |  |  | 10.02% | 9.88%
Equity income from unconsolidated investments, net | $ 6 |  |  |

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