Future Policy Benefit Reserves - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Insurance [Abstract]
Insurance claims and policyholders benefits, including policyholders' dividends, remeasurement impact	$ (33,000,000)	$ 1,000,000	$ (34,000,000)	$ 6,000,000
Liability for future policy benefit, expected future gross premium, discounted, before reinsurance	$ 3,853,000,000	$ 4,204,000,000	$ 3,853,000,000	$ 4,204,000,000
Liability for future policy benefit, weighted-average duration	12 years	12 years	12 years	12 years
Liability for future policy benefit, adverse development, expense	$ 29,000,000	$ 1,000,000	$ 42,000,000	$ 1,000,000
Liability future policy benefit, losses recognized in prior period	$ 1,000,000	$ 0	$ 11,000,000	$ 1,000,000