Reinsurance - Supplemental Information for Loss and Benefit Reserves, Gross and Net of Ceded Reinsurance (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
As Reported
Liability for unpaid losses and loss adjustment expenses	$ (70,666)	$ (69,168)	$ (70,393)	$ (75,167)
Future policy benefits	(1,385)	(1,317)
Unearned premiums	(17,991)	(17,232)
Other policyholder funds	(352)	(418)
Reinsurance assets	34,902	34,166
Net of Reinsurance
Liability for unpaid losses and loss adjustment expenses	(41,665)	(40,032)
Future policy benefits	(556)	(591)
Reserve for unearned premiums	(12,919)	(12,928)
Other policyholder funds	(352)	(418)
Reinsurance asset, allowance for credit loss	248	220
Reserve for liability to unpaid losses	130	110
Loss Recoveries
Net of Reinsurance
Contract claim recoverables	3,342	4,068
Contract Claims Recoverable
Net of Reinsurance
Contract claim recoverables	$ 0	$ 31