Investments (Maturities of Fixed Maturity Securities) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Available-for-sale Securities, Debt Maturities [Abstract]
Amortized Cost, Due in one year or less	$ 15,537	$ 15,828
Amortized Cost, Due after one year through five years	69,929	70,467
Amortized Cost, Due after five years through ten years	77,486	78,159
Amortized Cost, Due after ten years	103,564	103,405
Amortized Cost, Subtotal	266,516	267,859
Amortized Cost, RMBS, CMBS and ABS	66,026	65,740
Amortized cost of fixed maturity securities available-for-sale	332,542	333,599
Estimated Fair Value, Due in one year or less	15,723	16,030
Estimated Fair Value, Due after one year through five years	73,964	74,229
Estimated Fair Value, Due after five years through ten years	83,422	83,223
Estimated Fair Value, Due after ten years	114,112	109,529
Estimated Fair Value, Subtotal	287,221	283,011
Estimated fair value, Mortgage-backed and asset-backed securities	67,848	67,176
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $332,542 and $ 333,599, respectively; includes $4,152 and $4,005, respectively, relating to variable interest entities)	$ 355,069	$ 350,187