Investments - Schedule of Net Gains (Losses) on Derivatives and Investments (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Available-for-sale securities
Realized gains on sale	$ 4	$ 4	$ 11	$ 7
Realized losses on sale	(10)	(11)	(19)	(23)
Credit loss income (expense)	(8)	0	(16)	0
Credit loss income (expense) on mortgage loans	(20)	(10)	(46)	(21)
Other	13	(92)	2	(138)
Net gains (losses) excluding derivatives and funds withheld assets	(21)	(109)	(68)	(175)
Net gains (losses) on derivatives and investments	(2,487)	(2,860)	(2,204)	(1,517)
Net gains (losses) on funds withheld reinsurance treaties	(297)	(327)	(456)	(715)
Total net gains (losses) on derivatives and investments	(2,784)	(3,187)	(2,660)	(2,232)
Derivatives excluding funds withheld under reinsurance treaties and non-qualified voluntary deferred compensation plan
Available-for-sale securities
Net gains (losses) on derivative instruments	(2,466)	(2,751)	(2,136)	(1,342)
Derivatives related to funds withheld under reinsurance treaties
Available-for-sale securities
Net gains (losses) on derivative instruments	(117)	(179)	(99)	(397)
Net gains (losses) on funds withheld reinsurance treaties	$ (297)	$ (327)	$ (456)	$ (715)

Debt Securities, Available For Sale, Credit Loss Expense (Reversal)

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Financing Receivable, Credit Loss, Expense (Reversal) And Other (Gain) Loss

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Gain (Loss) On Investments And Derivative Instruments

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Gain (Loss) On Investments And Derivative Instruments, Net

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Other Operating Gain (Loss)

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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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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-9

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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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Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Amount of realized and unrealized gain (loss) on investment.

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Reference 3: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 230
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-Publisher FASB
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