Investments - Changes in Allowance for Credit Losses on Mortgage Loans on Real Estate (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance as of beginning-of-year	$ 152
Additions (reductions) from provision for credit loss expense	1	$ 0
Balance as of end-of-period	153
Commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance as of beginning-of-year	99
Balance as of end-of-period	97
Residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance as of beginning-of-year	53
Balance as of end-of-period	56
Mortgage loans on real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance as of beginning-of-year	152	114
Additions (reductions) from provision for credit loss expense	1	1
Additions from purchases of PCD mortgage loans on real estate	0	0
Balance as of end-of-period	153	115
Credit loss (expense) reversal	1	1
Accrued investment income excluded from credit losses	101	69
Mortgage loans on real estate | Commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance as of beginning-of-year	99	86
Additions (reductions) from provision for credit loss expense	(2)	(2)
Additions from purchases of PCD mortgage loans on real estate	0	0
Balance as of end-of-period	97	84
Mortgage loans on real estate | Residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance as of beginning-of-year	53	28
Additions (reductions) from provision for credit loss expense	3	3
Additions from purchases of PCD mortgage loans on real estate	0	0
Balance as of end-of-period	$ 56	$ 31