Investments (Maturities of Fixed Maturity Securities) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Available-for-sale Securities, Debt Maturities [Abstract]
Amortized Cost, Due in one year or less	$ 14,242	$ 15,828
Amortized Cost, Due after one year through five years	77,029	70,467
Amortized Cost, Due after five years through ten years	78,643	78,159
Amortized Cost, Due after ten years	102,352	103,405
Amortized Cost, Subtotal	272,266	267,859
Amortized Cost, RMBS, CMBS and ABS	67,021	65,740
Amortized Cost, Subtotal	339,287	333,599
Estimated Fair Value, Due in one year or less	14,480	16,030
Estimated Fair Value, Due after one year through five years	81,202	74,229
Estimated Fair Value, Due after five years through ten years	85,648	83,223
Estimated Fair Value, Due after ten years	116,223	109,529
Estimated Fair Value, Subtotal	297,553	283,011
Estimated fair value, Mortgage-backed and asset-backed securities	69,503	67,176
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $339,287 and $333,599, respectively; includes $4,180 and $4,005, respectively, relating to variable interest entities)	$ 367,056	$ 350,187