Investments (Net realized investment gains (losses)) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Fixed maturity securities:
Gross gains	$ 15	$ 11	$ 33	$ 38
Gross losses	(25)	(33)	(100)	(104)
Net investment gains (losses) on fixed maturity securities	(10)	(22)	(67)	(66)
Equity securities	4	13	10	25
Mortgage loans	0	0	(5)	0
Short-term investments and other	(1)	(1)	0	(1)
Net investment gains (losses)	(7)	(10)	(62)	(42)
Non-redeemable preferred stock
Net Investment Income [Line Items]
Net investment income (loss) recognized due to the change in fair value of common stock held as of September 30, 2025 and 2024	$ 4	$ 13	$ 8	$ 24

Investments and Derivatives, Realized Gain (Loss)

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Realized Gain (Loss) on Short Term Investments

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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).

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Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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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).

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Amount of unrealized and realized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of realized gain (loss) from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of credit loss expense (reversal of expense) for financing receivable.

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