Income Taxes - Changes in Gross Amounts of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions  | 
12 Months Ended | |
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Dec. 31, 2024  | 
Dec. 31, 2023  | 
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| Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | ||
| Balance at beginning of year | $ 73 | $ 74 | 
| Reductions for tax positions of prior years | (1) | (1) | 
| Balance at end of year | $ 72 | $ 73 | 
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available. 
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- Definition Amount of unrecognized tax benefits. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
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- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
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