Derivative Instruments (Details 2) (Customer-Related Positions [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2011 Year	Dec. 31, 2010 Year
Interest Rate Contracts [Member] | Receive fixed/pay floating swaps [Member]
Customer-related derivative positions of the company
Notional Value, Assets	$ 16,482	$ 15,730
Notional Value, Liabilities	239	1,294
Fair Value, Assets	1,270	956
Fair Value, Liabilities		21
Derivative Asset Average Remaining Maturity Period	5.05	4.64
Derivative Liability Average Remaining Maturity Period	2.80	6.01
Interest Rate Contracts [Member] | Pay fixed/receive floating swaps [Member]
Customer-related derivative positions of the company
Notional Value, Assets	217	1,315
Notional Value, Liabilities	16,572	15,769
Fair Value, Assets	1	24
Fair Value, Liabilities	1,241	922
Derivative Asset Average Remaining Maturity Period	3.94	6.12
Derivative Liability Average Remaining Maturity Period	5.07	4.68
Interest Rate Contracts [Member] | Purchased Option [Member]
Customer-related derivative positions of the company
Notional Value, Assets	2,191	2,024
Notional Value, Liabilities	100	115
Fair Value, Assets	5	13
Fair Value, Liabilities	23	12
Derivative Asset Average Remaining Maturity Period	1.85	1.98
Derivative Liability Average Remaining Maturity Period	0.08	0.36
Interest Rate Contracts [Member] | Written Option [Member]
Customer-related derivative positions of the company
Notional Value, Assets	369	472
Notional Value, Liabilities	1,962	1,667
Fair Value, Assets	23	12
Fair Value, Liabilities	5	13
Derivative Asset Average Remaining Maturity Period	0.20	0.26
Derivative Liability Average Remaining Maturity Period	2.04	2.35
Foreign Exchange Rate Contracts [Member] | Forwards, spots and swaps [Member]
Customer-related derivative positions of the company
Notional Value, Assets	13,166	7,772
Notional Value, Liabilities	12,357	7,694
Fair Value, Assets	457	384
Fair Value, Liabilities	456	360
Derivative Asset Average Remaining Maturity Period	0.41	0.74
Derivative Liability Average Remaining Maturity Period	0.39	0.75
Foreign Exchange Rate Contracts [Member] | Purchased Option [Member]
Customer-related derivative positions of the company
Notional Value, Assets	144	224
Fair Value, Assets	6	6
Derivative Asset Average Remaining Maturity Period	0.46	0.40
Foreign Exchange Rate Contracts [Member] | Written Option [Member]
Customer-related derivative positions of the company
Notional Value, Liabilities	144	224
Fair Value, Liabilities	$ 6	$ 6
Derivative Liability Average Remaining Maturity Period	0.46	0.40