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Investments (Unconsolidated Equity Investments) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Schedule of Equity Method Investments [Line Items] |  |  |
Carrying value | $ 542 | $ 508 | $ 476
Equity (income) / loss | (51) | (62) | (61)
ATC Holdings [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Carrying value | 358 | 338 |
Equity (income) / loss | $ (41) | (43) | (47)
ATC LLC [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Ownership interest | 16.00% |  |
ATC Holdco LLC [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Ownership interest | 20.00% |  |
Non-utility wind farm in Oklahoma [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Ownership interest | 50.00% |  |
Carrying value | $ 101 | 99 |
Equity (income) / loss | (5) | (4) | (8)
Corporate venture investments [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Carrying value | 62 | 52 |
Equity (income) / loss | (3) | (13) | (4)
Other [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Carrying value | 21 | 19 |
Equity (income) / loss | (2) | (2) | (2)
Total [Member] |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |
Carrying value | 542 | 508 |
Equity (income) / loss | $ (51) | $ (62) | $ (61)

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