Schedule V (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Reinsurance recoverables [Member]
Schedule V [Roll Forward]
Valuation and qualifying accounts, balance at beginning of period	$ 118	$ 132	$ 141
Valuation and qualifying accounts, charged to costs and expenses	1	(14)	(9)
Valuation and qualifying accounts, charged to other accounts	0	0	0
Valuation and qualifying accounts, deductions	0	0	0
Valuation and qualifying accounts, balance at end of period	119	118	132
Allowance for uncollectible premiums receivable from underwriting activities [Member]
Schedule V [Roll Forward]
Valuation and qualifying accounts, balance at beginning of period	69	77	107
Valuation and qualifying accounts, charged to costs and expenses	50	42	56
Valuation and qualifying accounts, charged to other accounts	0	0	(2)
Valuation and qualifying accounts, deductions	61	50	84
Valuation and qualifying accounts, balance at end of period	58	69	77
Allowance for uncollectible deductibles [Member]
Schedule V [Roll Forward]
Valuation and qualifying accounts, balance at beginning of period	29	25	29
Valuation and qualifying accounts, charged to costs and expenses	(1)	5	(3)
Valuation and qualifying accounts, charged to other accounts	0	0	0
Valuation and qualifying accounts, deductions	0	1	1
Valuation and qualifying accounts, balance at end of period	$ 28	$ 29	$ 25