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Nuclear Decommissioning Fund (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Debt Securities, Available-for-Sale, Unrealized Gain | $ 1,400 |  | $ 1,200 |
Debt Securities, Available-for-Sale, Unrealized Loss | 49 |  | 29 |
Equity investments in unconsolidated subsidiaries | 246 |  | 244 |
Miscellaneous investments | 156 |  | 144 |
Final Contractual Maturity [Abstract] |  |  |  |
Due in 1 Year or Less | 7 |  |  |
Due in 1 to 5 Years | 308 |  |  |
Due in 5 to 10 Years | 269 |  |  |
Due after 10 Years | 262 |  |  |
Total | 846 |  |  |
Fair Value Measured on a Recurring Basis | Cost |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Decommissioning fund investments | 2,130 | [1] | 2,054 | [2]
Fair Value Measured on a Recurring Basis | Cost | Cash equivalents |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Cash Equivalents | 39 | [1] | 41 | [2]
Fair Value Measured on a Recurring Basis | Cost | Commingled Funds |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Investments, Fair Value Disclosure | 703 | [1] | 721 | [2]
Fair Value Measured on a Recurring Basis | Cost | Debt Securities |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Debt Securities, Available-for-Sale, Excluding Accrued Interest | 866 | [1] | 784 | [2]
Fair Value Measured on a Recurring Basis | Cost | Equity Securities |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Equity Securities, FV-NI, Current | 522 | [1] | 508 | [2]
Fair Value Measured on a Recurring Basis | Fair Value |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Alternative Investment | 1,025 | [1] | 1,049 | [2]
Decommissioning fund investments | 3,494 | [1] | 3,211 | [2]
Final Contractual Maturity [Abstract] |  |  |  |
Total | 96 |  | 88 |
Fair Value Measured on a Recurring Basis | Fair Value | Cash equivalents |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Cash Equivalents | 39 | [1] | 41 | [2]
Alternative Investment | 0 | [1] | 0 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Commingled Funds |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Alternative Investment | 1,025 | [1] | 1,049 | [2]
Investments, Fair Value Disclosure | 1,025 | [1] | 1,049 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Debt Securities |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Alternative Investment | 0 | [1] | 0 | [2]
Debt Securities, Available-for-Sale, Excluding Accrued Interest | 846 | [1] | 780 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Equity Securities |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Alternative Investment | 0 | [1] | 0 | [2]
Equity Securities, FV-NI, Current | 1,584 | [1] | 1,341 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 1 |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Decommissioning fund investments | 1,622 | [1] | 1,380 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Cash equivalents |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Cash Equivalents | 39 | [1] | 41 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Commingled Funds |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Investments, Fair Value Disclosure | 0 | [1] | 0 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Debt Securities |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Debt Securities, Available-for-Sale, Excluding Accrued Interest | 0 | [1] | 0 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Equity Securities |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Equity Securities, FV-NI, Current | 1,583 | [1] | 1,339 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 2 |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Decommissioning fund investments | 833 | [1] | 773 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Cash equivalents |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Cash Equivalents | 0 | [1] | 0 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Commingled Funds |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Investments, Fair Value Disclosure | 0 | [1] | 0 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Debt Securities |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Debt Securities, Available-for-Sale, Excluding Accrued Interest | 832 | [1] | 771 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Equity Securities |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Equity Securities, FV-NI, Current | 1 | [1] | 2 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 3 |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Decommissioning fund investments | 14 | [1] | 9 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Cash equivalents |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Cash Equivalents | 0 | [1] | 0 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Commingled Funds |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Investments, Fair Value Disclosure | 0 | [1] | 0 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Debt Securities |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Debt Securities, Available-for-Sale, Excluding Accrued Interest | 14 | [1] | 9 | [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Equity Securities |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Equity Securities, FV-NI, Current | $ 0 | [1] | $ 0 | [2]
[1] | Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $246 million of equity method investments and $156 million of rabbi trust assets and other miscellaneous investments.
[2] | Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $244 million of equity investments in unconsolidated subsidiaries and $144 million of rabbi trust assets and other miscellaneous investments.

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