Derivative Financial Instruments (Details 1) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 Derivatives Designated as Hedging Instruments [Member]	Dec. 31, 2011 Derivatives Designated as Hedging Instruments [Member]	Jun. 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]	Jun. 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]	Jun. 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]	Jun. 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]	Jun. 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]	Jun. 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]	Jun. 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]	Jun. 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]	Jun. 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]	Jun. 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]	Jun. 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]	Jun. 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	$ 295,022	$ 290,021	$ 25,830	$ 21,904	$ 9,918	$ 9,630	$ 5,163	$ 4,580	$ 3,125	$ 3,220	$ 1,630	$ 1,830	$ 11,728	$ 10,585	$ 3,927	$ 3,230	$ 1,295	$ 965	$ 6,506	$ 6,370	$ 0	$ 20	$ 4,184	$ 1,689	$ 2,034	$ 1,689	$ 2,150	$ 0
Estimated Fair Value Assets	16,602	16,200	4,069	3,952	2,359	2,386	2,056	1,884	274	500	29	2	1,673	1,513	1,053	947	197	210	423	352	0	4	37	53	36	53	1	0
Estimated Fair Value Liabilities	$ 4,353	$ 4,011	$ 520	$ 518	$ 197	$ 200	$ 93	$ 92	$ 104	$ 98	$ 0	$ 10	$ 285	$ 306	$ 0	$ 0	$ 12	$ 0	$ 273	$ 306	$ 0	$ 0	$ 38	$ 12	$ 16	$ 12	$ 22	$ 0