Schedule VI. Supplemental Information Concerning Property and Casualty Insurance Operations (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Incurred claim and claim adjustment expenses related to current year	$ 4,904	$ 4,741	$ 4,793
Incurred claim and claim adjustment expenses related to prior years	(429)	(544)	(240)
Consolidated Property and Casualty Insurance Entity [Member]
Deferred acquisition costs	658	1,079
Reserves for unpaid claim and claim adjustment expenses	24,228	25,412
Discount deducted from claim and claim adjustment expense reserves above (based on interest rates ranging from 3.0% to 8.0%)	1,569	1,552
Unearned Premiums	3,250	3,203
Net written premiums	6,798	6,471	6,713
Net earned premiums	6,603	6,514	6,720
Net investment income	1,845	2,097	2,110
Incurred claim and claim adjustment expenses related to current year	4,901	4,737	4,788
Incurred claim and claim adjustment expenses related to prior years	(429)	(545)	(241)
Amortization of deferred acquisition costs	1,410	1,387	1,417
Paid claim and claim adjustment expenses	$ 4,499	$ 4,667	$ 4,841
Minimum interest rate in discount range	3.00%
Maximum interest rate in discount range	8.00%