Investments - Composition of Current and Past Due Mortgage Loans on Real Estate (Details) - USD ($)	Dec. 31, 2024	Dec. 31, 2023
Loans and Leases Receivable Disclosure [Line Items]
Allowance for credit losses	$ (152,000,000)	$ (114,000,000)
Unamortized premium (discount)	77,000,000	36,000,000
Mark-to-market gains (losses)	(31,000,000)	(38,000,000)
Total carrying value	21,083,000,000	18,963,000,000
Loans with fair value option in non-accrual, amortized cost	30,000,000	1,000,000
Loans with fair value option in non-accrual	21,000,000	1,000,000
Loans with fair value option, 90 days past due and still accruing	0	0
Current
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	20,954,000,000	18,921,000,000
30 to 59 days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	77,000,000	89,000,000
60 to 89 days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	33,000,000	9,000,000
90 or more days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	125,000,000	60,000,000
Commercial
Loans and Leases Receivable Disclosure [Line Items]
Allowance for credit losses	(99,000,000)	(86,000,000)
Unamortized premium (discount)	(6,000,000)	(7,000,000)
Mark-to-market gains (losses)	(31,000,000)	(37,000,000)
Total carrying value	17,472,000,000	17,187,000,000
Commercial | Current
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	17,567,000,000	17,256,000,000
Commercial | 30 to 59 days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	6,000,000	61,000,000
Commercial | 60 to 89 days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	0	0
Commercial | 90 or more days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	35,000,000	0
Residential
Loans and Leases Receivable Disclosure [Line Items]
Allowance for credit losses	(53,000,000)	(28,000,000)
Unamortized premium (discount)	83,000,000	43,000,000
Mark-to-market gains (losses)	0	(1,000,000)
Total carrying value	3,611,000,000	1,776,000,000
Residential | Current
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	3,387,000,000	1,665,000,000
Residential | 30 to 59 days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	71,000,000	28,000,000
Residential | 60 to 89 days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	33,000,000	9,000,000
Residential | 90 or more days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	$ 90,000,000	$ 60,000,000