Investments - Allowance for credit losses on fixed maturities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 9	$ 12
Initial allowance for purchased securities with credit deterioration	0	0
Provision for expected credit losses on securities with no previous allowance	0	0
Additions (reductions) to previously recognized expected credit losses	(2)	(1)
Reductions due to sales or redemptions	0	(1)
Ending balance	7	10
Structured securities
Allowance for Credit Losses [Roll Forward]
Beginning balance	8	10
Initial allowance for purchased securities with credit deterioration	0	0
Provision for expected credit losses on securities with no previous allowance	0	0
Additions (reductions) to previously recognized expected credit losses	(2)	(1)
Reductions due to sales or redemptions	0	0
Ending balance	6	9
Corporate and other
Allowance for Credit Losses [Roll Forward]
Beginning balance	1	2
Initial allowance for purchased securities with credit deterioration	0	0
Provision for expected credit losses on securities with no previous allowance	0	0
Additions (reductions) to previously recognized expected credit losses	0	0
Reductions due to sales or redemptions	0	(1)
Ending balance	$ 1	$ 1