Schedule V (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Allowance for premiums and insurances balances receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, Beginning of year	$ 127	$ 138	$ 168
Charged to Costs and Expenses	17	1	(7)
Write Offs	(16)	(12)	(28)
Other Changes	3	0	5
Balance, End of year	131	127	138
Federal and foreign valuation allowance for deferred tax assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, Beginning of year	1,650	1,745	2,594
Charged to Costs and Expenses	(305)	(31)	(365)
Write Offs	0	0	0
Other Changes	(294)	(64)	(484)
Balance, End of year	$ 1,051	$ 1,650	$ 1,745