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Investments - Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized gains (losses) on securities	$ 10	$ 0	$ (36)
Net of tax
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized gains (losses) on securities before impairments	21	21	(20)
Impairment allowance on securities	(13)	(21)	(8)
Realized gains (losses) on securities	8	0	(28)
Change in unrealized	180	85	210
Total pretax
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized gains (losses) on securities before impairments	26	27	(25)
Impairment allowance on securities	(16)	(27)	(11)
Realized gains (losses) on securities	10	0	(36)
Change in unrealized	227	108	267
Fixed maturities
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized gains (losses) on securities before impairments	(5)	(5)	(35)
Impairment allowance on fixed maturity securities	(14)	(27)	(10)
Realized gains (losses) on securities	(19)	(32)	(45)
Change in unrealized	227	108	267
Equity securities
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized gains (losses) on securities before impairments	31	32	10
Realized gains (losses) on securities	31	32	10
Change in unrealized	0	0	0
Mortgage loans and other investments
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized gains (losses) on securities before impairments	0	0	0
Impairment allowance on mortgage loans and other investments	(2)	0	(1)
Realized gains (losses) on securities	(2)	0	(1)
Change in unrealized	0	0	0
Tax effects
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized gains (losses) on securities before impairments	(5)	(6)	5
Impairment allowance on securities	3	6	3
Realized gains (losses) on securities	(2)	0	8
Change in unrealized	$ (47)	$ (23)	$ (57)

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Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments.

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Amount of realized gain (loss) on investment in debt and equity securities.

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Amount of increase (decrease) in allowance for credit loss of 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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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Amount of increase (decrease) in allowance for credit loss on financing receivable.

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