Investments (Gross Realized Gains and Losses From Sales Of Available-For-Sale Securities) (Detail) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
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| Investments [Abstract] | ||||
| Proceeds from sales | $ 0 | $ 2 | $ 0 | $ 125 |
| Available For Sale Securities Realized Gain Loss [Abstract] | ||||
| Gross realized gains | 0 | 0 | 0 | 1 |
| Gross realized losses | $ 0 | $ 0 | $ 0 | $ (7) |
| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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