Guaranteed Benefit Features - Net Amount at Risk of Minimum Guaranteed Benefits (Details) - Secondary Guarantees - Variable Life and Universal Life - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Net Amount at Risk by Product and Guarantee [Line Items]
Account value (general and separate account)	$ 1,333	$ 1,397
Net amount at risk, net of reinsurance	$ 3,775	$ 3,978
Weighted average attained age	73 years	72 years