Investments - Allowance for credit losses on fixed maturities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 16	$ 7	$ 11	$ 9
Provision for expected credit losses on securities with no previous allowance	0	1	6	1
Additions (reductions) to previously recognized expected credit losses	0	0	(1)	(2)
Reductions due to sales or redemptions	0	(1)	0	(1)
Ending balance	16	7	16	7
Structured securities
Allowance for Credit Losses [Roll Forward]
Beginning balance	11	6	10	8
Provision for expected credit losses on securities with no previous allowance	0	1	1	1
Additions (reductions) to previously recognized expected credit losses	0	0	0	(2)
Reductions due to sales or redemptions	0	0	0	0
Ending balance	11	7	11	7
Corporate and other
Allowance for Credit Losses [Roll Forward]
Beginning balance	5	1	1	1
Provision for expected credit losses on securities with no previous allowance	0	0	5	0
Additions (reductions) to previously recognized expected credit losses	0	0	(1)	0
Reductions due to sales or redemptions	0	(1)	0	(1)
Ending balance	$ 5	$ 0	$ 5	$ 0