Off-Balance Sheet - Standby Letters of Credit and Other Financial Guarantees (Details) (USD $)								12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Wholesale Loan [Member]	Dec. 31, 2011 Wholesale Loan [Member]	Dec. 31, 2012 Standby and Other Letters of Credit [Member]	Dec. 31, 2011 Standby and Other Letters of Credit [Member]	Dec. 31, 2012 Standby Letters of Credit, and Other Financial Guarantees [Member]	Dec. 31, 2011 Standby Letters of Credit, and Other Financial Guarantees [Member]	Dec. 31, 2012 Other Letters of Credit [Member]	Dec. 31, 2011 Other Letters of Credit [Member]	Dec. 31, 2012 Derivatives Qualifying As Guarantees [Member]	Dec. 31, 2011 Derivatives Qualifying As Guarantees [Member]
Standby letters of credit and other financial guarantees and other letters of credit [Abstract]
Standby and Other Letters of Credit, Carrying Value						$ 649,000,000	$ 698,000,000
Standby and Other Letters of Credit: Allowance						284,000,000	319,000,000
Guarantor Obligations, Current Carrying Value						365,000,000	379,000,000					42,000,000	457,000,000
Standby Letters of Credit and Other Financial Guarantees, Internal Credit Rating, Investment Grade								77,081,000,000	78,884,000,000	3,998,000,000	4,105,000,000
Standby Letters of Credit and Other Financial Guarantees, Internal Credit Rating, Non Investment Grade								23,848,000,000	23,015,000,000	1,575,000,000	1,281,000,000
Off-Balance Sheet Lending-Related Financial Commitments, Contractual Amount	1,027,988,000,000	975,662,000,000	958,709,000,000	434,814,000,000	382,739,000,000			100,929,000,000	101,899,000,000	5,573,000,000	5,386,000,000
Valuation Allowances and Reserves, Balance								282,000,000	317,000,000	2,000,000	2,000,000
Standby Letters of Credit, Collateral Held								42,654,000,000	41,529,000,000
Percentage of Cash or Liquid Collateral Relative to Value of Securities on Loan								100.00%
Other Letters of Credit, Collateral Held										1,145,000,000	1,264,000,000
Off balance sheet Lending related commitments Wholesale Contractual amount Net of Risk Participations Standby letters of credit and other financial guarantees								16,600,000,000	19,800,000,000
Off balance sheet Lending related commitments Wholesale Contractual amount Net of Risk Participations Other letters of credit										690,000,000	974,000,000
Standby Letters of Credit, Unissued Commitments	44,400,000,000	44,100,000,000
Derivatives qualifying as guarantees
Guarantee Obligations Maximum Exposure Derivatives												61,700,000,000	75,600,000,000
Derivative, Notional Amount	69,550,000,000,000	71,156,000,000,000										26,500,000,000	26,100,000,000
Derivatives Maximum Exposure To Loss												2,800,000,000	2,800,000,000
Derivative Qualifying As Guarantees Payables												122,000,000	555,000,000
Derivative Qualifying As Guarantees Receivables												$ 80,000,000	$ 98,000,000