Reserve for Property and Casualty Insurance Claims and Claims Expense - Rollforward of the reserve for property and casualty insurance claims and claims expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Incurred claims and claims expense related to:
Prior years	$ 866	$ 161	$ 1,470	$ (65)
National General
Activity in the reserve for property-liability insurance claims and claims expense:
National General acquisition as of January 4, 2021			0	1,797
Property-Liability
Activity in the reserve for property-liability insurance claims and claims expense:
Beginning balance			33,060	27,610
Less recoverables			(9,479)	(7,033)
Net balance as of January 1			23,581	20,577
Incurred claims and claims expense related to:
Current year			25,792	21,579
Prior years			1,470	(65)
Total incurred			27,262	21,514
Claims and claims expense paid related to:
Current year			(14,020)	(12,539)
Prior years			(9,850)	(8,098)
Total paid			(23,870)	(20,637)
Net balance as of September 30	26,973	23,251	26,973	23,251
Plus recoverables	9,556	10,035	9,556	10,035
Ending balance	$ 36,529	$ 33,286	$ 36,529	$ 33,286