Investments (Details 12) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Available-for-sale Securities, Debt Maturities [Abstract]
Amortized Cost, Due in one year or less	$ 19,016	$ 16,747
Amortized Cost, Due after one year through five years	63,283	62,819
Amortized Cost, Due after five years through ten years	82,469	82,694
Amortized Cost, Due after ten years	96,614	93,876
Amortized Cost, Subtotal	261,382	256,136
Amortized Cost, RMBS, CMBS and ABS	71,599	73,675
Amortized cost of fixed maturity securities available-for-sale	332,981	329,811
Estimated Fair Value, Due in one year or less	19,154	16,862
Estimated Fair Value, Due after one year through five years	65,588	64,414
Estimated Fair Value, Due after five years through ten years	89,080	88,036
Estimated Fair Value, Due after ten years	107,475	106,274
Estimated Fair Value, Subtotal	281,297	275,586
Estimated fair value, Mortgage-backed and asset-backed securities	73,154	74,685
Fixed maturity securities relating to variable interest entities	$ 354,451	$ 350,271