Schedule V (Details) - USD ($) $ in Millions		12 Months Ended
	Dec. 31, 2019	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2020
Schedule V [Roll Forward]
Reinsurance recoverables, allowance for estimated uncollectible reinsurance		$ 132	$ 141	$ 146
Accounting Standards Update [Extensible List]	Accounting Standards Update 2016-13 [Member]
Cumulative Effect, Period of Adoption, Adjustment [Member]
Schedule V [Roll Forward]
Reinsurance recoverables, allowance for estimated uncollectible reinsurance					$ 53
Reinsurance recoverables [Member]
Schedule V [Roll Forward]
Valuation and qualifying accounts, balance at beginning of period		141	146	92
Valuation and qualifying accounts, charged to costs and expenses		(9)	(5)	1
Valuation and qualifying accounts, charged to other accounts		0	0	53
Valuation and qualifying accounts, deductions		0	0	0
Valuation and qualifying accounts, balance at end of period	$ 92	132	141	146
Allowance for uncollectible premiums receivable from underwriting activities [Member]
Schedule V [Roll Forward]
Valuation and qualifying accounts, balance at beginning of period		107	105	55
Valuation and qualifying accounts, charged to costs and expenses		56	65	95
Valuation and qualifying accounts, charged to other accounts		(2)	0	2
Valuation and qualifying accounts, deductions		84	63	47
Valuation and qualifying accounts, balance at end of period	55	77	107	105
Allowance for uncollectible deductibles [Member]
Schedule V [Roll Forward]
Valuation and qualifying accounts, balance at beginning of period		29	27	22
Valuation and qualifying accounts, charged to costs and expenses		(3)	2	7
Valuation and qualifying accounts, charged to other accounts		0	0	(2)
Valuation and qualifying accounts, deductions		1	0	0
Valuation and qualifying accounts, balance at end of period	$ 22	$ 25	$ 29	$ 27