Investments (Details 12) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Available-for-sale Securities, Debt Maturities [Abstract]
Amortized Cost, Due in one year or less	$ 23,569	$ 16,747
Amortized Cost, Due after one year through five years	69,820	62,819
Amortized Cost, Due after five years through ten years	82,628	82,694
Amortized Cost, Due after ten years	96,682	93,876
Amortized Cost, Subtotal	272,699	256,136
Amortized Cost, RMBS, CMBS and ABS	72,092	73,675
Amortized cost of fixed maturity securities available-for-sale	344,791	329,811
Estimated Fair Value, Due in one year or less	23,771	16,862
Estimated Fair Value, Due after one year through five years	73,205	64,414
Estimated Fair Value, Due after five years through ten years	92,009	88,036
Estimated Fair Value, Due after ten years	113,984	106,274
Estimated Fair Value, Subtotal	302,969	275,586
Estimated fair value, Mortgage-backed and asset-backed securities	75,036	74,685
Fixed maturity securities relating to variable interest entities	$ 378,005	$ 350,271