Reinsurance and Indemnification - Premiums earned and life premiums and contract charges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Property and casualty insurance premiums
Reinsurance
Property and casualty insurance premiums earned	$ (495)	$ (456)	$ (941)	$ (883)
Accident and health insurance premiums and contract charges
Reinsurance
Accident and health insurance premiums and contract charges	$ (10)	$ (8)	$ (19)	$ (16)