Schedule VI (SUPPLEMENTARY INFORMATION CONCERNING PROPERTY AND CASUALTY OPERATIONS) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Supplemental Information for Property, Casualty Insurance Underwriters [Abstract]
Deferred Policy Acquisition Costs	$ 2,057	$ 1,865	$ 1,757
Net Reserves for Unpaid Losses	27,008	26,831	26,547
Unearned Premiums	8,222	7,539	6,864
Net Premiums Earned	16,445	15,708	14,764
Net Investment Income	2,071	1,977	2,018
Net Losses and Loss Expenses Incurred Related to Current Year	10,176	9,878	10,132
Net Losses and Loss Expenses Incurred Related to Prior Year	(527)	(530)	(479)
Amortization of Deferred Policy Acquisition Costs	2,805	2,447	2,254
Net Paid Losses and Loss Expenses	9,235	8,977	9,219
Net Premiums Written	$ 16,787	$ 16,069	$ 15,107