Investments - Investments - ACL on Fixed Maturities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss, Beginning Balance	$ 18	$ 13	$ 12	$ 1
Credit losses on fixed maturities where credit losses were not previously recorded	3	6	9	18
Reduction due to sales	(3)	(1)	(5)	(1)
Reduction due to intent to sell	0	(3)	0	(3)
Net increases (decreases) in allowance on fixed maturities that had an allowance in a previous period	2	0	4	0
Debt Securities, Available-for-sale, Allowance for Credit Loss, Ending Balance	20	15	20	15
Corporate
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss, Beginning Balance	6	8	2	1
Credit losses on fixed maturities where credit losses were not previously recorded	3	0	9	8
Reduction due to sales	(3)	0	(5)	0
Reduction due to intent to sell	0	0	0	0
Net increases (decreases) in allowance on fixed maturities that had an allowance in a previous period	2	0	2	(1)
Debt Securities, Available-for-sale, Allowance for Credit Loss, Ending Balance	8	8	8	8
Foreign Govt./Govt. Agencies
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss, Beginning Balance		4	0	0
Credit losses on fixed maturities where credit losses were not previously recorded		0		3
Reduction due to sales		(1)		(1)
Reduction due to intent to sell		(3)		(3)
Net increases (decreases) in allowance on fixed maturities that had an allowance in a previous period		0		1
Debt Securities, Available-for-sale, Allowance for Credit Loss, Ending Balance	0	0	0	0
CMBS
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss, Beginning Balance	12	1	10	0
Credit losses on fixed maturities where credit losses were not previously recorded	0	6	0	7
Reduction due to sales	0	0	0	0
Reduction due to intent to sell	0	0	0	0
Net increases (decreases) in allowance on fixed maturities that had an allowance in a previous period	0	0	2	0
Debt Securities, Available-for-sale, Allowance for Credit Loss, Ending Balance	$ 12	$ 7	$ 12	$ 7