Derivative Instruments (Details 1) (Asset and Liability Management Positions [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2011 Year	Dec. 31, 2010 Year
Fair Value Hedges [Member] | Foreign exchange cross-currency swaps [Member]
Asset and liability management derivative positions of the company
Notional Value, Assets	$ 895	$ 891
Notional Value, Liabilities	447	445
Fair Value, Assets	52	70
Fair Value, Liabilities	8
Derivative Asset Average Remaining Maturity Period	5.49	6.17
Derivative Liability Average Remaining Maturity Period	5.49	6.17
Fair Value Hedges [Member] | Interest Rate Contracts [Member] | Receive fixed/pay floating swaps [Member]
Asset and liability management derivative positions of the company
Notional Value, Assets	1,035	1,800
Fair Value, Assets	42	72
Derivative Asset Average Remaining Maturity Period	31.17	55.75
Cash flow hedges [Member] | Interest Rate Contracts [Member] | Pay fixed/receive floating swaps [Member]
Asset and liability management derivative positions of the company
Notional Value, Assets	750
Notional Value, Liabilities	11,039	4,788
Fair Value, Assets	1
Fair Value, Liabilities	845	688
Derivative Asset Average Remaining Maturity Period	3.05
Derivative Liability Average Remaining Maturity Period	3.67	5.03
Net investment hedges [Member] | Foreign exchange forward contracts [Member]
Asset and liability management derivative positions of the company
Notional Value, Assets	738	512
Fair Value, Assets	15	3
Derivative Asset Average Remaining Maturity Period	0.08	0.08
Derivative Liability Average Remaining Maturity Period		0
Other Economic Hedges [Member] | Credit Risk Contract [Member]
Asset and liability management derivative positions of the company
Notional Value, Assets	710	650
Notional Value, Liabilities	1,611	1,183
Fair Value, Assets	6	2
Fair Value, Liabilities	8	7
Derivative Asset Average Remaining Maturity Period	2.85	3.22
Derivative Liability Average Remaining Maturity Period	3.05	2.71
Other Economic Hedges [Member] | Equity Contract [Member]
Asset and liability management derivative positions of the company
Notional Value, Assets	30	61
Notional Value, Liabilities	31
Fair Value, Assets	2	3
Fair Value, Liabilities	5
Derivative Asset Average Remaining Maturity Period	1.53	1.60
Derivative Liability Average Remaining Maturity Period	0.88
Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Receive fixed/pay floating swaps [Member]
Asset and liability management derivative positions of the company
Notional Value, Assets	2,875	2,250
Fair Value, Assets	12	3
Derivative Asset Average Remaining Maturity Period	10.21	10.22
Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Pay fixed/receive floating swaps [Member]
Asset and liability management derivative positions of the company
Notional Value, Assets	250
Fair Value, Assets	4
Derivative Asset Average Remaining Maturity Period	10.21
Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Futures and Forwards Buy [Member]
Asset and liability management derivative positions of the company
Notional Value, Assets	12,832	2,879
Notional Value, Liabilities	691	6,312
Fair Value, Assets	132	20
Fair Value, Liabilities	4	79
Derivative Asset Average Remaining Maturity Period	0.08	0.10
Derivative Liability Average Remaining Maturity Period	0.05	0.05
Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Futures and Forwards Sell [Member]
Asset and liability management derivative positions of the company
Notional Value, Assets	2,893	9,082
Notional Value, Liabilities	9,732	6,002
Fair Value, Assets	9	207
Fair Value, Liabilities	126	51
Derivative Asset Average Remaining Maturity Period	0.14	0.07
Derivative Liability Average Remaining Maturity Period	0.12	0.09
Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Purchased Option [Member]
Asset and liability management derivative positions of the company
Notional Value, Assets	1,000	1,600
Derivative Asset Average Remaining Maturity Period	0.06	0.06
Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Written Option [Member]
Asset and liability management derivative positions of the company
Notional Value, Assets	4,664	6,321
Notional Value, Liabilities	13	1,348
Fair Value, Assets	79	23
Fair Value, Liabilities		9
Derivative Asset Average Remaining Maturity Period	0.14	0.07
Derivative Liability Average Remaining Maturity Period	0.16	0.07
Other Economic Hedges [Member] | Foreign exchange forward contracts [Member]
Asset and liability management derivative positions of the company
Notional Value, Assets	690	158
Notional Value, Liabilities	144	694
Fair Value, Assets	23	1
Fair Value, Liabilities	$ 1	$ 6
Derivative Asset Average Remaining Maturity Period	0.09	0.09
Derivative Liability Average Remaining Maturity Period	0.10	0.09