Investments (Details 12) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Available-for-sale Securities, Debt Maturities [Abstract]
Amortized Cost, Due in one year or less	$ 18,012	$ 16,747
Amortized Cost, Due after one year through five years	70,897	62,819
Amortized Cost, Due after five years through ten years	80,653	82,694
Amortized Cost, Due after ten years	97,134	93,876
Amortized Cost, Subtotal	266,696	256,136
Amortized Cost, RMBS, CMBS and ABS	72,175	73,675
Amortized cost of fixed maturity securities available-for-sale	338,871	329,811
Estimated Fair Value, Due in one year or less	18,173	16,862
Estimated Fair Value, Due after one year through five years	73,297	64,414
Estimated Fair Value, Due after five years through ten years	88,403	88,036
Estimated Fair Value, Due after ten years	112,493	106,274
Estimated Fair Value, Subtotal	292,366	275,586
Estimated fair value, Mortgage-backed and asset-backed securities	73,973	74,685
Fixed maturity securities relating to variable interest entities	$ 366,339	$ 350,271