Investments - Schedule of Net Investment Gains (Losses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Available-for-sale fixed maturity securities:
Realized gains	$ 29	$ 49	$ 29
Realized losses	(79)	(106)	(154)
Net realized gains (losses) on available-for-sale fixed maturity securities	(50)	(57)	(125)
Net realized gains (losses) on equity securities sold	5	9	(1)
Total net realized investment gains (losses)	(45)	(48)	(126)
Net change in allowance for credit losses on available-for-sale fixed maturity securities	(13)	(3)	(7)
Write-down of available-for-sale fixed maturity securities	(4)	(9)	(1)
Net unrealized gains (losses) on equity securities still held	56	83	53
Net unrealized gains (losses) on limited partnerships	112	43	111
Commercial mortgage loans	(23)	(16)	(5)
Derivative instruments	(17)	(18)	7
Other	(7)	(19)	(9)
Net investment gains (losses)	$ 59	$ 13	$ 23