Reinsurance - Rollforward of the reinsurance recoverable allowance for credit losses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 391	$ 374	$ 382	$ 375
Addition to (release of) allowance for expected credit losses and disputes, net	5	20	12	24
Write-offs charged against the allowance for credit losses and disputes	(1)	(8)	(3)	(15)
Recoveries of amounts previously written off	0	0	2	0
Other changes	(1)	2	1	4
Balance, end of period	394	388	394	388
General Insurance
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	284	287	281	292
Addition to (release of) allowance for expected credit losses and disputes, net	4	5	5	5
Write-offs charged against the allowance for credit losses and disputes	(1)	(8)	(3)	(15)
Recoveries of amounts previously written off	0	0	2	0
Other changes	(1)	2	1	4
Balance, end of period	286	286	286	286
Life and Retirement
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	107	87	101	83
Addition to (release of) allowance for expected credit losses and disputes, net	1	15	7	19
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	$ 108	$ 102	$ 108	$ 102