Schedule VI. Supplemental Information Concerning Property and Casualty Insurance Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Incurred claim and claim adjustment expenses related to current year	$ 6,243	$ 5,970	$ 5,793
Incurred claim and claim adjustment expenses related to prior years	(187)	(104)	(119)
Consolidated Property and Casualty Insurance Entity
Deferred acquisition costs	806	737
Reserves for unpaid claim and claim adjustment expenses	25,099	24,174
Discount deducted from claim and claim adjustment expense reserves above (based on interest rates ranging from 3.5% to 6.4%)	1,133	1,146
Unearned premiums	6,374	5,761
Net written premiums	9,128	8,405	8,059
Net earned premiums	8,667	8,175	7,649
Net investment income	1,751	2,111	1,896
Incurred claim and claim adjustment expenses related to current year		5,970	5,793
Incurred claim and claim adjustment expenses related to prior years		(104)	(119)
Amortization of deferred acquisition costs	$ 1,490	1,443	1,410
Paid claim and claim adjustment expenses		$ 4,844	$ 5,164
Consolidated Property and Casualty Insurance Entity | Minimum
Supplemental Information Parenthetical
SEC Schedule, 12-18, supplemental information, property-casualty insurance underwriters, interest rate at which discount computed	3.50%	3.50%
Consolidated Property and Casualty Insurance Entity | Maximum
Supplemental Information Parenthetical
SEC Schedule, 12-18, supplemental information, property-casualty insurance underwriters, interest rate at which discount computed	6.40%	6.40%