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Business Developments And Risks And Uncertainties (Narrative) (Detail) $ / shares in Units, $ in Millions |  |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | ---
Jan. 01, 2024 USD ($) | Dec. 07, 2023 USD ($) $ / shares | Nov. 30, 2023 USD ($) | Mar. 31, 2023 USD ($) | Dec. 31, 2023 USD ($) Segments | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Jun. 26, 2023 USD ($)
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Number of operating segments | Segments |  |  |  |  | 3 |  |  |
Correction of error income (loss) from discontinued operations, net of tax |  |  |  | $ 18 |  |  |  |
Dividends paid |  |  |  |  | $ 409 | $ 0 | $ 0 |
Dividend declared per common share | $ / shares |  | $ 8 |  |  |  |  |  |
Dividend payment date |  |  |  |  | Dec. 22, 2023 |  |  |
Special Dividend [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Dividends paid |  | $ 550 |  |  |  |  |  |
Right Dividend [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Dividends paid |  |  | $ 97 |  |  |  |  |
Noncontrolling Interest [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Correction of error income (loss) from discontinued operations, net of tax |  |  |  | $ 8 |  |  |  |
Puerto Rico Electric Power Authority [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Claims payments |  |  |  |  | $ 137 |  |  |
Outstanding bonds |  |  |  |  | $ 808 |  |  |
Subsequent Event | Puerto Rico Electric Power Authority [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Claims payments | $ 16 |  |  |  |  |  |  |
Maximum [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Liabilities Subject to Compromise, Provision for Expected and Allowed Claims |  |  |  |  |  |  |  | $ 7,600
Minimum [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Liabilities Subject to Compromise, Provision for Expected and Allowed Claims |  |  |  |  |  |  |  | $ 2,400

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