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Nuclear Decommissioning Trust Fund - Summary of Aggregate Fair Values and Realized Gains and Losses (Details) - USD ($) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2022 | Dec. 31, 2023 | Nov. 01, 2023
Nuclear decommissioning trust fund disclosure |  |  |
Fair Value | $ 838 | $ 0 |
Unrealized Gains | 346 |  |
Unrealized Losses | 36 |  |
Cash and cash equivalents |  |  |
Nuclear decommissioning trust fund disclosure |  |  |
Fair Value | 15 |  |
Unrealized Gains | 0 |  |
Unrealized Losses | 0 |  |
U.S. government and federal agency obligations |  |  |
Nuclear decommissioning trust fund disclosure |  |  |
Fair Value | 86 |  |
Unrealized Gains | 0 |  |
Unrealized Losses | $ 5 |  |
Weighted- average maturities (in years) | 11 years |  |
Federal agency mortgage-backed securities |  |  |
Nuclear decommissioning trust fund disclosure |  |  |
Fair Value | $ 101 |  |
Unrealized Gains | 0 |  |
Unrealized Losses | $ 11 |  |
Weighted- average maturities (in years) | 26 years |  |
Commercial mortgage-backed securities |  |  |
Nuclear decommissioning trust fund disclosure |  |  |
Fair Value | $ 35 |  |
Unrealized Gains | 0 |  |
Unrealized Losses | $ 4 |  |
Weighted- average maturities (in years) | 30 years |  |
Corporate debt securities |  |  |
Nuclear decommissioning trust fund disclosure |  |  |
Fair Value | $ 114 |  |
Unrealized Gains | 0 |  |
Unrealized Losses | $ 13 |  |
Weighted- average maturities (in years) | 12 years |  |
Equity securities |  |  |
Nuclear decommissioning trust fund disclosure |  |  |
Fair Value | $ 486 |  |
Unrealized Gains | 346 |  |
Unrealized Losses | 3 |  |
Foreign government fixed income securities |  |  |
Nuclear decommissioning trust fund disclosure |  |  |
Fair Value | 1 |  |
Unrealized Gains | 0 |  |
Unrealized Losses | $ 0 |  |
Weighted- average maturities (in years) | 17 years |  |
South Texas Project |  |  |
Nuclear decommissioning trust fund disclosure |  |  |
Ownership Interest (as a percent) |  |  | 44.00%

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- Definition The fair value of investments held in a trust fund to pay for the costs of decontaminating and decommissioning facilities, whether such amount is presented as a separate caption or as a parenthetical disclosure on the balance sheet. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481850/410-20-50-1 + Details
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- Definition The proportionate share of interest (percent) in a jointly owned utility plant. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 360 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 10.C) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479960/980-360-S99-1 + Details
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