Schedule VI (SUPPLEMENTARY INFORMATION CONCERNING PROPERTY AND CASUALTY OPERATIONS) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Abstract]
Deferred Policy Acquisition Costs	$ 3,346	$ 2,877	$ 2,718
Net Reserves for Unpaid Losses	62,238	58,661	56,198
Unearned Premiums	22,051	19,713	18,496
Net Premiums Earned	40,314	36,850	33,953
Net Investment Income	4,181	3,233	3,049
Current Year Claim and Claim Adjustment Expense	24,956	23,680	21,986
Prior Year Claim and Claim Adjustment Expense	(856)	(1,108)	(956)
Net Losses and Loss Expenses Incurred Related to Prior Year	(882)
Amortization of Deferred Policy Acquisition Costs	7,391	6,480	5,945
Net Paid Losses and Loss Expenses	21,011	19,537	16,948
Net Premiums Written	$ 41,896	$ 38,112	$ 35,391