Investments - Rollforward of credit loss allowance for mortgage loans (Details) - Mortgage loans on real estate - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ (67)	$ (3)
Net decreases related to credit losses	40	(39)
Reduction of allowance related to sales	21	17
Write-offs	0	0
Ending balance	(6)	(67)
Discontinued Operations, Held-for-sale
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Roll Forward]
Beginning balance	(59)
Ending balance		(59)
Cumulative effect of change in accounting principle
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 0	(42)
Ending balance		$ 0