Schedule VI (SUPPLEMENTARY INFORMATION CONCERNING PROPERTY AND CASUALTY OPERATIONS) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplemental Information for Property, Casualty Insurance Underwriters [Abstract]
Deferred Policy Acquisition Costs	$ 3,537	$ 2,219	$ 2,057
Net Reserves for Unpaid Losses	47,832	26,562	27,008
Unearned Premiums	14,779	8,439	8,222
Net Premiums Earned	27,747	16,282	16,445
Net Investment Income	2,656	2,007	2,071
Net Losses and Loss Expenses Incurred Related to Current Year	17,256	10,030	10,176
Net Losses and Loss Expenses Incurred Related to Prior Year	(1,204)	(546)	(527)
Amortization of Deferred Policy Acquisition Costs	5,654	2,692	2,805
Net Paid Losses and Loss Expenses	15,715	9,665	9,235
Net Premiums Written	$ 27,074	$ 16,734	$ 16,787