Fair Value Measurement - Level 3 Analysis (Details 3) (USD $) In Millions, unless otherwise specified		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended				3 Months Ended	6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended		6 Months Ended	3 Months Ended		6 Months Ended	3 Months Ended			6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013 Asset Backed Securities Trading Account [Member]	Jun. 30, 2012 Asset Backed Securities Trading Account [Member]	Jun. 30, 2013 Asset Backed Securities Trading Account [Member]	Jun. 30, 2012 Asset Backed Securities Trading Account [Member]	Jun. 30, 2013 Derivative Receivables Net Of Payables [ Member]	Jun. 30, 2012 Derivative Receivables Net Of Payables [ Member]	Jun. 30, 2013 Derivative Receivables Net Of Payables [ Member]	Jun. 30, 2012 Derivative Receivables Net Of Payables [ Member]	Jun. 30, 2013 Derivative Receivables Net Of Payables [ Member] Fair Value, Inputs, Level 3 [Member]	Jun. 30, 2013 Mortgage servicing rights [Member]	Jun. 30, 2012 Mortgage servicing rights [Member]	Jun. 30, 2013 Mortgage servicing rights [Member]	Jun. 30, 2012 Mortgage servicing rights [Member]	Jun. 30, 2013 Asset backed Security Available for Sale [Member]	Jun. 30, 2012 Asset backed Security Available for Sale [Member]	Jun. 30, 2013 Asset backed Security Available for Sale [Member]	Jun. 30, 2012 Asset backed Security Available for Sale [Member]	Jun. 30, 2013 Credit derivatives	Jun. 30, 2012 Credit derivatives	Jun. 30, 2013 Credit derivatives	Jun. 30, 2012 Credit derivatives	Jun. 30, 2013 Equity Contract	Jun. 30, 2012 Equity Contract	Jun. 30, 2013 Equity Contract	Jun. 30, 2012 Equity Contract	Jun. 30, 2013 Interest Rate Contract [Member]	Jun. 30, 2012 Interest Rate Contract [Member]	Jun. 30, 2013 Interest Rate Contract [Member]	Jun. 30, 2012 Interest Rate Contract [Member]	Jun. 30, 2013 Foreign exchange contract	Jun. 30, 2012 Foreign exchange contract	Jun. 30, 2013 Foreign exchange contract	Jun. 30, 2012 Foreign exchange contract	Jun. 30, 2013 Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Fair Value, Measurements, Recurring [Member]	Jun. 30, 2013 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member]	Jun. 30, 2013 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 31, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member]	Jun. 30, 2013 Fair Value, Measurements, Recurring [Member] Derivative Receivables Net Of Payables [ Member]	Jun. 30, 2012 Fair Value, Measurements, Recurring [Member] Derivative Receivables Net Of Payables [ Member]	Jun. 30, 2013 Fair Value, Measurements, Recurring [Member] Mortgage servicing rights [Member]	Jun. 30, 2012 Fair Value, Measurements, Recurring [Member] Mortgage servicing rights [Member]	Jun. 30, 2012 Fair Value, Measurements, Recurring [Member] Credit derivatives	Jun. 30, 2013 Fair Value, Measurements, Recurring [Member] Equity Contract	Jun. 30, 2013 Fair Value, Measurements, Recurring [Member] Interest Rate Contract [Member]	Jun. 30, 2012 Fair Value, Measurements, Recurring [Member] Interest Rate Contract [Member]	Jun. 30, 2013 Debt and Equity Instruments [Member] Fair Value, Measurements, Recurring [Member]	Jun. 30, 2013 Long-term debt	Jun. 30, 2012 Long-term debt	Jun. 30, 2013 Long-term debt	Jun. 30, 2012 Long-term debt
Level 3 Analysis
Percentage of Level 3 Assets To Total Assets	2.80%
Assets, Fair Value Disclosure, Recurring																																			$ 813,709	$ 882,235	$ 65,748	$ 65,748	$ 98,123
Increase (Decrease) In Level 3 Assets				(2,300)						(4,800)	1,400		1,700				(26,900)				(2,100)								(1,500)				(1,000)				(728)	(32,400)		(3,500)					(1,000)	(1,100)		1,700
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		95	(218)	159	12	(104)	2,362	818	749			(1,119)	1,347	(523)	0	(339)	5	(336)	(335)	168	(824)	(2,186)	(350)	885	513	165	125	2,027	431	3,355	161	(632)	45	(505)							749	1,038	(1,100)	(2,200)			3,400
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings																																																	$ 430	$ 191	$ 905	$ 52