Reinsurance - GMIB Reinsurers (Details) - GMIB - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Berkshire | Secured | GMIB Assets | Collateralization risk
Ceded Credit Risk [Line Items]
Concentration percentage	100.00%
Liberty Re (Bermuda) Ltd. | Secured | GMIB Assets | Collateralization risk
Ceded Credit Risk [Line Items]
Concentration percentage	100.00%
Other Contract [Member]
Ceded Credit Risk [Line Items]
GMIB recoverables	$ 601	$ 758
Other Contract [Member] | Berkshire
Ceded Credit Risk [Line Items]
GMIB recoverables	283	353
Other Contract [Member] | Sun Life Assurance Company of Canada
Ceded Credit Risk [Line Items]
GMIB recoverables	167	215
Other Contract [Member] | Liberty Re (Bermuda) Ltd.
Ceded Credit Risk [Line Items]
GMIB recoverables	$ 151	$ 190