Reinsurance and Indemnification - Schedule of Effects of Reinsurance Ceded and Indemnification Programs on Property and Casualty Premiums Earned and Accident and Health Insurance Premiums and Contract Charges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Property and casualty insurance premiums earned
Reinsurance
Property and casualty insurance premiums earned	$ (608)	$ (588)	$ (1,151)	$ (1,145)
Accident and health insurance premiums and contract charges
Reinsurance
Accident and health insurance premiums and contract charges	$ (10)	$ (11)	$ (23)	$ (21)

Amount of earned premiums ceded to other entities.

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+ Details