Investments - Schedule of Rollforward of Credit Loss Allowance for Fixed Income Securities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Ending balance	$ (5)	$ (22)	$ (5)	$ (22)
Fixed income securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Beginning balance	(17)	(19)	(17)	(36)
Credit losses on securities for which credit losses not previously reported	0	(3)	(1)	(10)
Net (increases) decreases related to credit losses previously reported	0	0	1	3
(Increase) decrease related to sales and other	0	0	0	3
Write-offs	12	0	12	18
Ending balance	(5)	(22)	(5)	(22)
Municipal bonds
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Ending balance	0	(2)	0	(2)
Corporate bonds
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Ending balance	(4)	(18)	(4)	(18)
ABS
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Ending balance	$ (1)	$ (2)	$ (1)	$ (2)