Investment Information - Allowance for expected credit losses (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Allowance for expected credit losses
Balance at beginning of period				$ 41
Balance at end of period		$ 57		57
Fixed maturities
Allowance for expected credit losses
Balance at beginning of period		61	$ 59	41	$ 3
Additions for current-period provision for expected credit losses		6	4	7	53
Additions (reductions) for previously recognized expected credit losses		(3)	(13)	18	(6)
Reductions due to disposals		(7)	(4)	(9)	(4)
Balance at end of period		57	46	57	46
Fixed maturities | Structured securities
Allowance for expected credit losses
Balance at beginning of period	[1]	8	19	9	1
Additions for current-period provision for expected credit losses	[1]	2	2	2	13
Additions (reductions) for previously recognized expected credit losses	[1]	0	(10)	(1)	(3)
Reductions due to disposals	[1]	(2)	(2)	(2)	(2)
Balance at end of period	[1]	8	9	8	9
Fixed maturities | Corporate bonds
Allowance for expected credit losses
Balance at beginning of period		50	40	30	2
Additions for current-period provision for expected credit losses		4	2	5	40
Additions (reductions) for previously recognized expected credit losses		(3)	(3)	18	(3)
Reductions due to disposals		(4)	(2)	(6)	(2)
Balance at end of period		47	37	47	37
Fixed maturities | Non-U.S. government securities
Allowance for expected credit losses
Balance at beginning of period		3	0	2	0
Additions for current-period provision for expected credit losses		0	0	0	0
Additions (reductions) for previously recognized expected credit losses		0	0	1	0
Reductions due to disposals		(1)	0	(1)	0
Balance at end of period		$ 2	$ 0	$ 2	$ 0

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