Investments (Rollforward of the Allowance for Credit Losses for Fixed Maturity Securities by Sector) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, allowance for credit losses, beginning of period	$ 79	$ 21
Allowance on securities where credit losses were not previously recorded	2	35
Reductions for securities sold	(4)	0
Change in allowance on securities with an allowance recorded in a previous period	12	3
Write-offs charged against allowance (1)	(27)	0
Fixed maturity securities, allowance for credit losses, end of period	62	59
U.S. corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, allowance for credit losses, beginning of period	47	15
Allowance on securities where credit losses were not previously recorded	2	13
Reductions for securities sold	(3)	0
Change in allowance on securities with an allowance recorded in a previous period	7	3
Write-offs charged against allowance (1)	(27)	0
Fixed maturity securities, allowance for credit losses, end of period	26	31
Foreign corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, allowance for credit losses, beginning of period	26	0
Allowance on securities where credit losses were not previously recorded	0	21
Reductions for securities sold	0	0
Change in allowance on securities with an allowance recorded in a previous period	6	0
Write-offs charged against allowance (1)	0	0
Fixed maturity securities, allowance for credit losses, end of period	32	21
RMBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, allowance for credit losses, beginning of period	4	4
Allowance on securities where credit losses were not previously recorded	0	0
Reductions for securities sold	0	0
Change in allowance on securities with an allowance recorded in a previous period	(1)	0
Write-offs charged against allowance (1)	0	0
Fixed maturity securities, allowance for credit losses, end of period	3	4
CMBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, allowance for credit losses, beginning of period	2	2
Allowance on securities where credit losses were not previously recorded	0	1
Reductions for securities sold	(1)	0
Change in allowance on securities with an allowance recorded in a previous period	0	0
Write-offs charged against allowance (1)	0	0
Fixed maturity securities, allowance for credit losses, end of period	$ 1	$ 3