Investments - Allowance for credit losses on fixed maturities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 11	$ 9	$ 12
Provision for expected credit losses on securities with no previous allowance	9	5	1
Reductions to previously recognized expected credit losses	1	(2)	(2)
Reductions due to sales or redemptions	9	1	2
Ending balance	12	11	9
Structured securities
Allowance for Credit Losses [Roll Forward]
Beginning balance	10	8	10
Provision for expected credit losses on securities with no previous allowance	1	4	0
Reductions to previously recognized expected credit losses	2	(2)	(2)
Reductions due to sales or redemptions	4	0	0
Ending balance	9	10	8
Corporate and other
Allowance for Credit Losses [Roll Forward]
Beginning balance	1	1	2
Provision for expected credit losses on securities with no previous allowance	8	1	1
Reductions to previously recognized expected credit losses	(1)	0	0
Reductions due to sales or redemptions	5	1	2
Ending balance	$ 3	$ 1	$ 1