Investments (Net realized investment gains (losses)) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Fixed maturity securities:
Gross gains	$ 5	$ 13	$ 18	$ 27
Gross losses	(53)	(25)	(75)	(71)
Net investment gains (losses) on fixed maturity securities	(48)	(12)	(57)	(44)
Equity securities	6	1	6	12
Short-term investments and other	1	1	1	0
Net investment gains (losses)	(46)	(10)	(55)	(32)
Net Investment Income [Line Items]
Gross gains	5	13	18	27
Debt Securities, Available-for-sale, Realized Loss	53	25	75	71
Debt Securities, Available-for-sale, Realized Gain (Loss)	(48)	(12)	(57)	(44)
Equity securities	6	1	6	12
Mortgage loans	(5)	0	(5)	0
Short-term investments and other	1	1	1	0
Net investment losses	(46)	(10)	(55)	(32)
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 June 30, 2025 and 2024	$ 6	$ 1	$ 4	$ 12

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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-Topic 320
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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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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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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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