Investments - Allowance for credit losses on fixed maturities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 10	$ 16	$ 12	$ 11
Provision for expected credit losses on securities with no previous allowance	15	3	16	9
Additions to previously recognized expected credit losses	0	1	1	0
Reductions due to sales or redemptions	0	0	(4)	0
Ending balance	25	20	25	20
Structured securities
Allowance for Credit Losses [Roll Forward]
Beginning balance	10	11	9	10
Provision for expected credit losses on securities with no previous allowance	0	0	1	1
Additions to previously recognized expected credit losses	0	1	1	1
Reductions due to sales or redemptions	0	0	(1)	0
Ending balance	10	12	10	12
Corporate and other
Allowance for Credit Losses [Roll Forward]
Beginning balance	0	5	3	1
Provision for expected credit losses on securities with no previous allowance	15	3	15	8
Additions to previously recognized expected credit losses	0	0	0	(1)
Reductions due to sales or redemptions	0	0	(3)	0
Ending balance	$ 15	$ 8	$ 15	$ 8