Investment Information - Allowance for expected credit losses (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Balance at beginning of period		$ 41
Balance at end of period		28	$ 41
Fixed maturities
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Balance at beginning of period		41	3
Additions for current-period provision for expected credit losses		7	55
Additions (reductions) for previously recognized expected credit losses		(10)	(13)
Reductions due to disposals		(10)	(4)
Balance at end of period		28	41
Structured securities
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Balance at beginning of period	[1]	9	1
Additions for current-period provision for expected credit losses	[1]	2	14
Additions (reductions) for previously recognized expected credit losses	[1]	(3)	(4)
Reductions due to disposals	[1]	(1)	(2)
Balance at end of period	[1]	7	9
Non-US government securities
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Balance at beginning of period		2	0
Additions for current-period provision for expected credit losses		0	2
Additions (reductions) for previously recognized expected credit losses		0	0
Reductions due to disposals		(1)	0
Balance at end of period		1	2
Corporate bonds
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Balance at beginning of period		30	2
Additions for current-period provision for expected credit losses		5	39
Additions (reductions) for previously recognized expected credit losses		(7)	(9)
Reductions due to disposals		(8)	(2)
Balance at end of period		$ 20	$ 30

[1] Includes asset backed securities, mortgage backed securities and commercial mortgage backed securities.