Derivative Financial Instruments (Details 1) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Derivatives Designated as Hedging Instruments [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member]	Mar. 31, 2012 Derivatives Designated as Hedging Instruments [Member] Fair Value Hedges [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Fair Value Hedges [Member]	Mar. 31, 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]	Mar. 31, 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]	Mar. 31, 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]	Mar. 31, 2012 Derivatives Designated as Hedging Instruments [Member] Cash Flow Hedges [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Cash Flow Hedges [Member]	Mar. 31, 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]	Mar. 31, 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]	Mar. 31, 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]	Mar. 31, 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]	Mar. 31, 2012 Derivatives Designated as Hedging Instruments [Member] Foreign Operations Hedges [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member] Foreign Operations Hedges [Member]	Mar. 31, 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]	Mar. 31, 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	$ 289,962	$ 290,021	$ 24,083	$ 21,904	$ 9,464	$ 9,630	$ 4,835	$ 4,580	$ 3,249	$ 3,220	$ 1,380	$ 1,830	$ 11,464	$ 10,585	$ 3,775	$ 3,230	$ 1,160	$ 965	$ 6,529	$ 6,370	$ 0	$ 20	$ 3,155	$ 1,689	$ 2,405	$ 1,689	$ 750	$ 0
Estimated Fair Value Assets	12,447	16,200	3,164	3,952	2,155	2,386	1,615	1,884	540	500	0	2	969	1,513	614	947	111	210	244	352	0	4	40	53	34	53	6	0
Estimated Fair Value Liabilities	$ 4,207	$ 4,011	$ 568	$ 518	$ 234	$ 200	$ 85	$ 92	$ 80	$ 98	$ 69	$ 10	$ 306	$ 306	$ 0	$ 0	$ 0	$ 0	$ 306	$ 306	$ 0	$ 0	$ 28	$ 12	$ 26	$ 12	$ 2	$ 0