Investments (Maturities of Fixed Maturity Securities) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Available-for-sale Securities, Debt Maturities [Abstract]
Amortized Cost, Due in one year or less	$ 14,389	$ 15,828
Amortized Cost, Due after one year through five years	76,630	70,467
Amortized Cost, Due after five years through ten years	79,346	78,159
Amortized Cost, Due after ten years	102,942	103,405
Amortized Cost, Subtotal	273,307	267,859
Amortized Cost, RMBS, CMBS and ABS	67,891	65,740
Amortized Cost, Subtotal	341,198	333,599
Estimated Fair Value, Due in one year or less	14,603	16,030
Estimated Fair Value, Due after one year through five years	80,212	74,229
Estimated Fair Value, Due after five years through ten years	85,438	83,223
Estimated Fair Value, Due after ten years	117,696	109,529
Estimated Fair Value, Subtotal	297,949	283,011
Estimated fair value, Mortgage-backed and asset-backed securities	70,121	67,176
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $341,198 and $333,599, respectively; includes $4,097 and $4,005, respectively, relating to variable interest entities)	$ 368,070	$ 350,187