Future Policy Benefit Reserves - Earned Premiums and Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Insurance [Abstract]
Earned premiums	$ 113	$ 118	$ 228	$ 238
Interest expense	$ 189	$ 189	$ 379	$ 377