Investments - Allowance for credit losses on fixed maturities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 12	$ 11	$ 9
Provision for expected credit losses on securities with no previous allowance	26	9	5
Additions (reductions) to previously recognized expected credit losses	1	1	(2)
Reductions due to sales or redemptions	(5)	(9)	(1)
Ending balance	34	12	11
Structured securities
Allowance for Credit Losses [Roll Forward]
Beginning balance	9	10	8
Provision for expected credit losses on securities with no previous allowance	1	1	4
Additions (reductions) to previously recognized expected credit losses	1	2	(2)
Reductions due to sales or redemptions	0	(4)	0
Ending balance	11	9	10
Corporate and other
Allowance for Credit Losses [Roll Forward]
Beginning balance	3	1	1
Provision for expected credit losses on securities with no previous allowance	25	8	1
Additions (reductions) to previously recognized expected credit losses	0	(1)	0
Reductions due to sales or redemptions	(5)	(5)	(1)
Ending balance	$ 23	$ 3	$ 1