Derivative Financial Instruments (Details 1) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Derivatives Designated as Hedging Instruments [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member]	Sep. 30, 2012 Derivatives Designated as Hedging Instruments [Member] Fair Value Hedges [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Fair Value Hedges [Member]	Sep. 30, 2012 Derivatives Designated as Hedging Instruments [Member] Fair Value Hedges [Member] Interest rate swaps [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Fair Value Hedges [Member] Interest rate swaps [Member]	Sep. 30, 2012 Derivatives Designated as Hedging Instruments [Member] Fair Value Hedges [Member] Foreign currency swaps [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Fair Value Hedges [Member] Foreign currency swaps [Member]	Sep. 30, 2012 Derivatives Designated as Hedging Instruments [Member] Fair Value Hedges [Member] Foreign currency forwards [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Fair Value Hedges [Member] Foreign currency forwards [Member]	Sep. 30, 2012 Derivatives Designated as Hedging Instruments [Member] Cash Flow Hedges [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Cash Flow Hedges [Member]	Sep. 30, 2012 Derivatives Designated as Hedging Instruments [Member] Cash Flow Hedges [Member] Interest rate swaps [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Cash Flow Hedges [Member] Interest rate swaps [Member]	Sep. 30, 2012 Derivatives Designated as Hedging Instruments [Member] Cash Flow Hedges [Member] Interest rate forwards [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Cash Flow Hedges [Member] Interest rate forwards [Member]	Sep. 30, 2012 Derivatives Designated as Hedging Instruments [Member] Cash Flow Hedges [Member] Foreign currency swaps [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Cash Flow Hedges [Member] Foreign currency swaps [Member]	Sep. 30, 2012 Derivatives Designated as Hedging Instruments [Member] Cash Flow Hedges [Member] Credit forwards [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Cash Flow Hedges [Member] Credit forwards [Member]	Sep. 30, 2012 Derivatives Designated as Hedging Instruments [Member] Foreign Operations Hedges [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Foreign Operations Hedges [Member]	Sep. 30, 2012 Derivatives Designated as Hedging Instruments [Member] Foreign Operations Hedges [Member] Foreign currency forwards [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Foreign Operations Hedges [Member] Foreign currency forwards [Member]	Sep. 30, 2012 Derivatives Designated as Hedging Instruments [Member] Foreign Operations Hedges [Member] Currency options [Member]	Mar. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Foreign Operations Hedges [Member] Currency options [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	$ 303,246	$ 290,021	$ 29,462	$ 21,904	$ 10,973	$ 9,630	$ 5,306	$ 4,580	$ 3,187	$ 3,220	$ 2,480	$ 1,830	$ 13,465	$ 10,585	$ 3,792	$ 3,230	$ 770	$ 965	$ 8,903	$ 6,370	$ 0	$ 20	$ 5,024	$ 1,689	$ 2,374	$ 1,689	$ 2,650	$ 0
Estimated Fair Value Assets	15,728	16,200	3,728	3,952	2,368	2,386	2,036	1,884	312	500	20	2	1,355	1,513	896	947	178	210	281	352	0	4	5	53	4	53	1	0
Estimated Fair Value Liabilities	$ 4,711	$ 4,011	$ 641	$ 518	$ 179	$ 200	$ 100	$ 92	$ 79	$ 98	$ 0	$ 10	$ 363	$ 306	$ 0	$ 0	$ 0	$ 0	$ 363	$ 306	$ 0	$ 0	$ 99	$ 12	$ 53	$ 12	$ 46	$ 0