Schedule VI (SUPPLEMENTARY INFORMATION CONCERNING PROPERTY AND CASUALTY OPERATIONS) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental Information for Property, Casualty Insurance Underwriters [Abstract]
Deferred Policy Acquisition Costs	$ 2,219	$ 2,057	$ 1,865
Net Reserves for Unpaid Losses	26,562	27,008	26,831
Unearned Premiums	8,439	8,222	7,539
Net Premiums Earned	16,282	16,445	15,708
Net Investment Income	2,007	2,071	1,977
Net Losses and Loss Expenses Incurred Related to Current Year	10,030	10,176	9,878
Net Losses and Loss Expenses Incurred Related to Prior Year	(546)	(527)	(530)
Amortization of Deferred Policy Acquisition Costs	2,692	2,805	2,447
Net Paid Losses and Loss Expenses	9,665	9,235	8,977
Net Premiums Written	$ 16,734	$ 16,787	$ 16,069