Reinsurance - Rollforward of the reinsurance recoverable allowance for credit losses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 327	$ 391	$ 344	$ 382
Addition to (release of) allowance for expected credit losses and disputes, net	(9)	(2)	(22)	7
Write-offs charged against the allowance for credit losses and disputes	0	0	(1)	(2)
Recoveries of amounts previously written off	0	2	0	2
Other changes	2	0	(1)	2
Balance, end of period	320	391	320	391
General Insurance
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	253	286	260	281
Addition to (release of) allowance for expected credit losses and disputes, net	(1)	(4)	(4)	1
Write-offs charged against the allowance for credit losses and disputes	0	0	(1)	(2)
Recoveries of amounts previously written off	0	2	0	2
Other changes	2	0	(1)	2
Balance, end of period	254	284	254	284
Life and Retirement
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	74	105	84	101
Addition to (release of) allowance for expected credit losses and disputes, net	(8)	2	(18)	6
Write-offs charged against the allowance for credit losses and disputes	0	0	0	0
Recoveries of amounts previously written off	0	0	0	0
Other changes	0	0	0	0
Balance, end of period	$ 66	$ 107	$ 66	$ 107