Investments - Allowance for credit losses on fixed maturities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 7	$ 9	$ 9	$ 12
Initial allowance for purchased securities with credit deterioration	0	0	0	0
Provision for expected credit losses on securities with no previous allowance	2	0	3	0
Additions (reductions) to previously recognized expected credit losses	0	0	(2)	(1)
Reductions due to sales or redemptions	0	0	(1)	(2)
Ending balance	9	9	9	9
Structured securities
Allowance for Credit Losses [Roll Forward]
Beginning balance	7	8	8	10
Initial allowance for purchased securities with credit deterioration	0	0	0	0
Provision for expected credit losses on securities with no previous allowance	2	0	3	0
Additions (reductions) to previously recognized expected credit losses	0	0	(2)	(2)
Reductions due to sales or redemptions	0	0	0	0
Ending balance	9	8	9	8
Corporate and other
Allowance for Credit Losses [Roll Forward]
Beginning balance	0	1	1	2
Initial allowance for purchased securities with credit deterioration	0	0	0	0
Provision for expected credit losses on securities with no previous allowance	0	0	0	0
Additions (reductions) to previously recognized expected credit losses	0	0	0	1
Reductions due to sales or redemptions	0	0	(1)	(2)
Ending balance	$ 0	$ 1	$ 0	$ 1