Reserves for Future Policy Benefits and Claims Payable - Rollforward of Additional Liabilities, Closed Block Life (Details) - Closed Block Life - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of year	$ 1,172,000,000	$ 1,159,000,000	$ 1,159,000,000
Effect of changes in cash flow assumptions	0	6,000,000
Effect of expected policyholder behavior	12,000,000		58,000,000
Interest accrual	14,000,000	56,000,000	56,000,000
Net assessments collected	(57,000,000)	(107,000,000)	(107,000,000)
Balance, end of year	1,141,000,000		1,172,000,000
As Previously Reported
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of year	1,131,000,000	1,173,000,000	1,173,000,000
Balance, end of year	1,117,000,000		1,131,000,000
Cumulative effect of changes in shadow adjustments
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of year	(41,000,000)	$ 14,000,000	14,000,000
Balance, end of year	$ (24,000,000)		$ (41,000,000)