Schedule VI. Supplemental Information Concerning Property and Casualty Insurance Operations (Details) (Consolidated Property and Casualty Insurance Entity [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Consolidated Property and Casualty Insurance Entity [Member]
Deferred acquisition costs	$ 624	$ 598
Reserves for unpaid claim and claim adjustment expenses	24,015	24,696
Discount deducted from claim and claim adjustment expense reserves above (based on interest rates ranging from 3.0% to 9.7%)	1,586	1,850
Unearned Premiums	3,718	3,610
Net written premiums	7,348	6,964	6,798
Net earned premiums	7,271	6,881	6,603
Net investment income	2,240	2,074	1,845
Incurred claim and claim adjustment expenses related to current year	5,113	5,266	4,901
Incurred claim and claim adjustment expenses related to prior years	(115)	(180)	(429)
Amortization of deferred acquisition costs	1,362	1,274	1,176
Paid claim and claim adjustment expenses	$ 5,566	$ 5,257	$ 4,499
Supplemental Information Parenthetical
Minimum interest rate in discount range	3.00%
Maximum interest rate in discount range	9.70%