Fair Value Measurement - Carrying Value and Estimated Fair Value (Details 7) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2010
Financial assets
Cash and due from banks	$ 44,866,000,000	$ 30,466,000,000	$ 44,866,000,000	$ 30,466,000,000		$ 59,602,000,000		$ 27,567,000,000
Deposits with banks	130,383,000,000		130,383,000,000			85,279,000,000
Federal funds sold and securities purchased under resale agreements (included $32,862 and $24,891 at fair value)	255,188,000,000		255,188,000,000			235,314,000,000
Mortgage servicing rights at fair value	7,118,000,000	12,243,000,000	7,118,000,000	12,243,000,000	8,039,000,000	7,223,000,000	13,093,000,000	13,649,000,000
Trading assets and liabilities average balances Abstract
Trading assets - debt and equity instruments	346,708,000,000	422,715,000,000	351,021,000,000	420,103,000,000
Trading assets - derivative receivables	89,345,000,000	82,860,000,000	89,896,000,000	84,141,000,000
Trading liabilities - debt and equity instruments	69,763,000,000	84,250,000,000	69,374,000,000	83,588,000,000
Trading liabilities - derivative payables	78,704,000,000	66,009,000,000	77,387,000,000	68,634,000,000
Fair Value, Measurements, Recurring [Member]
Financial assets
Trading assets	417,324,000,000		417,324,000,000			443,963,000,000
Mortgage servicing rights at fair value	7,118,000,000		7,118,000,000			7,223,000,000
Financial liabilities
Trading liabilities	147,061,000,000		147,061,000,000			141,695,000,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Financial assets
Securities borrowed	0		0			0
Trading assets	56,779,000,000		56,779,000,000			68,008,000,000
Loans, at fair value	2,520,000,000		2,520,000,000			1,647,000,000
Mortgage servicing rights at fair value	7,118,000,000		7,118,000,000			7,223,000,000
Financial liabilities
Deposits	1,876,000,000		1,876,000,000			1,418,000,000
Federal funds purchased and securities loaned or sold under repurchase agreements (included $9.5 and $4.1 at fair value)	0		0			0
Trading liabilities	23,677,000,000		23,677,000,000			29,014,000,000
Accounts payable and other liabilities	42,000,000		42,000,000			51,000,000
Beneficial interests issued by consolidated VIEs, at fair value	745,000,000		745,000,000			791,000,000
Long-term debt and junior subordinated deferrable interest debentures	8,856,000,000		8,856,000,000			10,310,000,000
Fair value | Fair Value, Measurements, Recurring [Member]
Financial assets
Loans, at fair value	3,010,000,000		3,010,000,000			2,097,000,000
Carrying value
Financial assets
Cash and due from banks	44,900,000,000		44,900,000,000			59,600,000,000
Deposits with banks	130,400,000,000		130,400,000,000			85,300,000,000
Accrued interest and accounts receivable	67,900,000,000		67,900,000,000			61,500,000,000
Federal funds sold and securities purchased under resale agreements (included $32,862 and $24,891 at fair value)	222,300,000,000		222,300,000,000			210,400,000,000
Securities borrowed	126,700,000,000		126,700,000,000			127,200,000,000
Loans, at fair value	700,800,000,000		700,800,000,000			694,000,000,000
Other	52,200,000,000		52,200,000,000			49,800,000,000
Financial liabilities
Deposits	1,110,600,000,000		1,110,600,000,000			1,122,900,000,000
Federal funds purchased and securities loaned or sold under repurchase agreements (included $9.5 and $4.1 at fair value)	246,100,000,000		246,100,000,000			204,000,000,000
Commercial paper	50,600,000,000		50,600,000,000			51,600,000,000
Other borrowed funds	10,900,000,000		10,900,000,000			12,300,000,000
Accounts payable and other liabilities	171,800,000,000		171,800,000,000			166,900,000,000
Beneficial interests issued by consolidated VIEs, at fair value	54,100,000,000		54,100,000,000			64,700,000,000
Long-term debt and junior subordinated deferrable interest debentures	207,900,000,000		207,900,000,000			222,100,000,000
Wholesale lending related commitments	800,000,000		800,000,000			700,000,000
EstimateOfFairValueFairValueDisclosureNotCarriedAtFairValue [Member]
Financial assets
Cash and due from banks	44,900,000,000		44,900,000,000			59,600,000,000
Deposits with banks	130,400,000,000		130,400,000,000			85,300,000,000
Accrued interest and accounts receivable	67,900,000,000		67,900,000,000			61,500,000,000
Federal funds sold and securities purchased under resale agreements (included $32,862 and $24,891 at fair value)	222,300,000,000		222,300,000,000			210,400,000,000
Securities borrowed	126,700,000,000		126,700,000,000			127,200,000,000
Loans, at fair value	702,300,000,000		702,300,000,000			693,700,000,000
Other	52,600,000,000		52,600,000,000			50,300,000,000
Financial liabilities
Deposits	1,111,100,000,000		1,111,100,000,000			1,123,400,000,000
Federal funds purchased and securities loaned or sold under repurchase agreements (included $9.5 and $4.1 at fair value)	246,100,000,000		246,100,000,000			204,000,000,000
Commercial paper	50,600,000,000		50,600,000,000			51,600,000,000
Other borrowed funds	10,900,000,000		10,900,000,000			12,300,000,000
Accounts payable and other liabilities	171,700,000,000		171,700,000,000			166,800,000,000
Beneficial interests issued by consolidated VIEs, at fair value	54,200,000,000		54,200,000,000			64,900,000,000
Long-term debt and junior subordinated deferrable interest debentures	208,300,000,000		208,300,000,000			219,500,000,000
Wholesale lending related commitments	3,300,000,000		3,300,000,000			3,400,000,000
EstimateOfFairValueFairValueDisclosureNotCarriedAtFairValue [Member] | EstimateOfFairValueLevel1Inputs [Member]
Financial assets
Cash and due from banks	44,900,000,000		44,900,000,000
Deposits with banks	113,300,000,000		113,300,000,000
Accrued interest and accounts receivable	0		0
Federal funds sold and securities purchased under resale agreements (included $32,862 and $24,891 at fair value)	0		0
Securities borrowed	0		0
Loans, at fair value	0		0
Other	0		0
Financial liabilities
Deposits	0		0
Federal funds purchased and securities loaned or sold under repurchase agreements (included $9.5 and $4.1 at fair value)	0		0
Commercial paper	0		0
Other borrowed funds	0		0
Accounts payable and other liabilities	0		0
Beneficial interests issued by consolidated VIEs, at fair value	0		0
Long-term debt and junior subordinated deferrable interest debentures	0		0
Wholesale lending related commitments	0		0
EstimateOfFairValueFairValueDisclosureNotCarriedAtFairValue [Member] | Estimate of Fair Value, Predominantly Level 2 Inputs [Member]
Financial assets
Cash and due from banks	0		0
Deposits with banks	17,100,000,000		17,100,000,000
Accrued interest and accounts receivable	64,600,000,000		64,600,000,000
Federal funds sold and securities purchased under resale agreements (included $32,862 and $24,891 at fair value)	222,300,000,000		222,300,000,000
Securities borrowed	126,700,000,000		126,700,000,000
Loans, at fair value	24,700,000,000		24,700,000,000
Other	44,800,000,000		44,800,000,000
Financial liabilities
Deposits	1,110,000,000,000		1,110,000,000,000
Federal funds purchased and securities loaned or sold under repurchase agreements (included $9.5 and $4.1 at fair value)	246,100,000,000		246,100,000,000
Commercial paper	50,600,000,000		50,600,000,000
Other borrowed funds	10,700,000,000		10,700,000,000
Accounts payable and other liabilities	162,900,000,000		162,900,000,000
Beneficial interests issued by consolidated VIEs, at fair value	49,300,000,000		49,300,000,000
Long-term debt and junior subordinated deferrable interest debentures	203,300,000,000		203,300,000,000
Wholesale lending related commitments	0		0
EstimateOfFairValueFairValueDisclosureNotCarriedAtFairValue [Member] | Estimate of Fair Value, Level 3 Inputs [Member]
Financial assets
Cash and due from banks	0		0
Deposits with banks	0		0
Accrued interest and accounts receivable	3,300,000,000		3,300,000,000
Federal funds sold and securities purchased under resale agreements (included $32,862 and $24,891 at fair value)	0		0
Securities borrowed	0		0
Loans, at fair value	677,600,000,000		677,600,000,000
Other	7,800,000,000		7,800,000,000
Financial liabilities
Deposits	1,100,000,000		1,100,000,000
Federal funds purchased and securities loaned or sold under repurchase agreements (included $9.5 and $4.1 at fair value)	0		0
Commercial paper	0		0
Other borrowed funds	200,000,000		200,000,000
Accounts payable and other liabilities	8,800,000,000		8,800,000,000
Beneficial interests issued by consolidated VIEs, at fair value	4,900,000,000		4,900,000,000
Long-term debt and junior subordinated deferrable interest debentures	5,000,000,000		5,000,000,000
Wholesale lending related commitments	$ 3,300,000,000		$ 3,300,000,000