Fair Value Measurement - Recurring Basis (Details) (USD $)	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Mortgage servicing rights	$ 9,335,000,000	$ 7,949,000,000	$ 7,614,000,000	$ 7,118,000,000	$ 8,039,000,000	$ 7,223,000,000
Other Short-term Borrowings	30,385,000,000		26,636,000,000
Fair value assets and liabilities measured on recurring basis - supplemental data
Reduction In Level Three Derivative Receivable And Derivative Payable Balances	7,000,000,000		7,400,000,000
Costs of the private equity investment portfolio	8,600,000,000		8,400,000,000
Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	401,470,000,000		450,028,000,000
Mortgage servicing rights	9,335,000,000		7,614,000,000
Total assets measured at fair value on a recurring basis	813,709,000,000		882,235,000,000
Trading liabilities	148,593,000,000		131,918,000,000
Total liabilities at fair value on a recurring basis	201,959,000,000		185,624,000,000
Fair value assets and liabilities measured on recurring basis - supplemental data
Investment valued at net asset value	3,900,000,000		4,900,000,000
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0		0
Securities borrowed	0		0
Trading assets	152,291,000,000		159,512,000,000
Available-for-sale securities	53,433,000,000		43,413,000,000
Loans, at fair value	0		0
Mortgage servicing rights	0		0
Total assets measured at fair value on a recurring basis	210,168,000,000		207,691,000,000
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
Other Short-term Borrowings	0		0
Trading liabilities	66,691,000,000		48,563,000,000
Accounts payable and other liabilities	0		0
Beneficial interests issued by consolidated VIEs, at fair value	0		0
Long-term debt	0		0
Total liabilities at fair value on a recurring basis	66,691,000,000		48,563,000,000
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	25,306,000,000		24,258,000,000
Securities borrowed	5,295,000,000		10,177,000,000
Trading assets	1,482,904,000,000		1,831,942,000,000
Available-for-sale securities	299,337,000,000		298,816,000,000
Loans, at fair value	80,000,000		273,000,000
Mortgage servicing rights	0		0
Total assets measured at fair value on a recurring basis	1,813,354,000,000		2,165,719,000,000
Deposits	3,648,000,000		3,750,000,000
Federal funds purchased and securities loaned or sold under repurchase agreements (included $9.5 and $4.1 at fair value)	4,661,000,000		4,388,000,000
Other Short-term Borrowings	9,899,000,000		9,972,000,000
Trading liabilities	1,331,687,000,000		1,633,613,000,000
Accounts payable and other liabilities	0		0
Beneficial interests issued by consolidated VIEs, at fair value	180,000,000		245,000,000
Long-term debt	20,018,000,000		22,312,000,000
Total liabilities at fair value on a recurring basis	1,370,093,000,000		1,674,280,000,000
Fair value assets and liabilities measured on recurring basis - supplemental data
Investment valued at net asset value	1,000,000,000		1,100,000,000
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0		0
Securities borrowed	0		0
Trading assets	41,836,000,000		47,872,000,000
Available-for-sale securities	1,949,000,000		28,916,000,000
Loans, at fair value	1,843,000,000		2,282,000,000
Mortgage servicing rights	9,335,000,000		7,614,000,000
Total assets measured at fair value on a recurring basis	65,748,000,000		98,123,000,000
Deposits	2,190,000,000		1,983,000,000
Federal funds purchased and securities loaned or sold under repurchase agreements (included $9.5 and $4.1 at fair value)	0		0
Other Short-term Borrowings	2,673,000,000		1,619,000,000
Trading liabilities	17,949,000,000		20,545,000,000
Accounts payable and other liabilities	32,000,000		36,000,000
Beneficial interests issued by consolidated VIEs, at fair value	863,000,000		925,000,000
Long-term debt	9,202,000,000		8,476,000,000
Total liabilities at fair value on a recurring basis	32,909,000,000		33,584,000,000
Fair value assets and liabilities measured on recurring basis - supplemental data
Investment valued at net asset value	2,900,000,000		3,800,000,000
Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0		0
Securities borrowed	0		0
Trading assets	(1,275,561,000,000)		(1,589,298,000,000)
Available-for-sale securities	0		0
Loans, at fair value	0		0
Mortgage servicing rights	0		0
Total assets measured at fair value on a recurring basis	(1,275,561,000,000)		(1,589,298,000,000)
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
Other Short-term Borrowings	0		0
Trading liabilities	(1,267,734,000,000)		(1,570,803,000,000)
Accounts payable and other liabilities	0		0
Beneficial interests issued by consolidated VIEs, at fair value	0		0
Long-term debt	0		0
Total liabilities at fair value on a recurring basis	(1,267,734,000,000)		(1,570,803,000,000)
Fair value | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	25,306,000,000		24,258,000,000
Securities borrowed	5,295,000,000		10,177,000,000
Available-for-sale securities	354,719,000,000		371,145,000,000
Loans, at fair value	1,923,000,000		2,555,000,000
Deposits	5,838,000,000		5,733,000,000
Federal funds purchased and securities loaned or sold under repurchase agreements (included $9.5 and $4.1 at fair value)	4,661,000,000		4,388,000,000
Other Short-term Borrowings	12,572,000,000		11,591,000,000
Accounts payable and other liabilities	32,000,000		36,000,000
Long-term debt	29,220,000,000		30,788,000,000
Total debt and equity instruments [Member] | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	327,719,000,000		375,045,000,000
Trading liabilities	84,208,000,000		61,262,000,000
Total debt and equity instruments [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	147,909,000,000		158,270,000,000
Trading liabilities	62,868,000,000		47,469,000,000
Total debt and equity instruments [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	155,403,000,000		191,136,000,000
Trading liabilities	21,236,000,000		13,588,000,000
Total debt and equity instruments [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	24,407,000,000		25,639,000,000
Trading liabilities	104,000,000		205,000,000
Total debt and equity instruments [Member] | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Trading liabilities	0		0
Total debt instruments [Member] | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	221,717,000,000		243,827,000,000
Total debt instruments [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	54,535,000,000		41,265,000,000
Total debt instruments [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	144,935,000,000		178,900,000,000
Total debt instruments [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	22,247,000,000		23,662,000,000
Total debt instruments [Member] | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Mortgage-backed securities | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	34,941,000,000		41,682,000,000
Available-for-sale securities	179,862,000,000		186,230,000,000
Mortgage-backed securities | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
Mortgage-backed securities | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	32,154,000,000		39,314,000,000
Available-for-sale securities	179,225,000,000		185,525,000,000
Mortgage-backed securities | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	2,787,000,000		2,368,000,000
Available-for-sale securities	637,000,000		705,000,000
Mortgage-backed securities | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
US Government Corporations and Agencies Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	30,001,000,000		36,738,000,000
Available-for-sale securities	101,314,000,000		98,388,000,000
US Government Corporations and Agencies Securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
US Government Corporations and Agencies Securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	29,100,000,000		36,240,000,000
Available-for-sale securities	101,314,000,000		98,388,000,000
US Government Corporations and Agencies Securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	901,000,000		498,000,000
Available-for-sale securities	0		0
US Government Corporations and Agencies Securities [Member] | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
Residential mortgage | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	2,398,000,000		2,172,000,000
Available-for-sale securities	65,564,000,000		74,639,000,000
Residential mortgage | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
Residential mortgage | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	1,783,000,000		1,509,000,000
Available-for-sale securities	65,179,000,000		74,189,000,000
Residential mortgage | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	615,000,000		663,000,000
Available-for-sale securities	385,000,000		450,000,000
Residential mortgage | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
Commercial - nonagency | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	2,542,000,000		2,772,000,000
Available-for-sale securities	12,984,000,000		13,203,000,000
Commercial - nonagency | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
Commercial - nonagency | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	1,271,000,000		1,565,000,000
Available-for-sale securities	12,732,000,000		12,948,000,000
Commercial - nonagency | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	1,271,000,000		1,207,000,000
Available-for-sale securities	252,000,000		255,000,000
Commercial - nonagency | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
U.S. Treasury and government agencies | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	37,460,000,000		22,425,000,000
Available-for-sale securities	22,898,000,000		12,130,000,000
U.S. Treasury and government agencies | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	25,932,000,000		15,170,000,000
Available-for-sale securities	22,115,000,000		11,089,000,000
U.S. Treasury and government agencies | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	11,528,000,000		7,255,000,000
Available-for-sale securities	783,000,000		1,041,000,000
U.S. Treasury and government agencies | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
U.S. Treasury and government agencies | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
Obligations of U.S. states and municipalities | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	12,487,000,000		18,162,000,000
Available-for-sale securities	24,533,000,000		21,711,000,000
Obligations of U.S. states and municipalities | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	71,000,000		35,000,000
Obligations of U.S. states and municipalities | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	11,266,000,000		16,726,000,000
Available-for-sale securities	24,275,000,000		21,489,000,000
Obligations of U.S. states and municipalities | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	1,221,000,000		1,436,000,000
Available-for-sale securities	187,000,000		187,000,000
Obligations of U.S. states and municipalities | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
Certificates Of Deposit Bankers Acceptances Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	2,471,000,000		4,759,000,000
Certificates Of Deposit Bankers Acceptances Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Certificates Of Deposit Bankers Acceptances Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	2,471,000,000		4,759,000,000
Certificates Of Deposit Bankers Acceptances Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Certificates Of Deposit Bankers Acceptances Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Certificates of Deposit | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	1,588,000,000		2,783,000,000
Certificates of Deposit | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	0		0
Certificates of Deposit | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	1,588,000,000		2,783,000,000
Certificates of Deposit | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	0		0
Certificates of Deposit | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	0		0
Non-U.S. government debt securities | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	58,523,000,000		70,190,000,000
Available-for-sale securities	55,974,000,000		66,044,000,000
Non-U.S. government debt securities | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	28,603,000,000		26,095,000,000
Available-for-sale securities	28,637,000,000		29,556,000,000
Non-U.S. government debt securities | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	29,784,000,000		44,028,000,000
Available-for-sale securities	27,337,000,000		36,488,000,000
Non-U.S. government debt securities | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	136,000,000		67,000,000
Available-for-sale securities	0		0
Non-U.S. government debt securities | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
Corporate Debt Securities | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	31,895,000,000		37,190,000,000
Available-for-sale securities	28,239,000,000		38,609,000,000
Corporate Debt Securities | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
Corporate Debt Securities | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	26,160,000,000		31,882,000,000
Available-for-sale securities	28,239,000,000		38,609,000,000
Corporate Debt Securities | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	5,735,000,000		5,308,000,000
Available-for-sale securities	0		0
Corporate Debt Securities | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
Loans | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	38,626,000,000		41,541,000,000
Loans | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Loans | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	27,686,000,000		30,754,000,000
Loans | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	10,940,000,000		10,787,000,000
Loans | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Residential Mortgage [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	21,400,000,000		26,400,000,000
Reverse Mortgage [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	3,500,000,000		4,000,000,000
Residential Conforming Mortgage Intended for Sale to Government Agency [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	13,500,000,000		17,400,000,000
Wholesale Loan [Member] | Trading assets
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	1,900,000,000		2,200,000,000
Asset-backed securities | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	5,314,000,000		7,878,000,000
Asset-backed securities | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Asset-backed securities | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	3,886,000,000		4,182,000,000
Asset-backed securities | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	1,428,000,000		3,696,000,000
Asset-backed securities | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Collateralized loan obligations | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	27,318,000,000		27,896,000,000
Collateralized loan obligations | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	0		0
Collateralized loan obligations | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	26,330,000,000		0
Collateralized loan obligations | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	988,000,000		27,896,000,000
Collateralized loan obligations | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	0		0
Other, Debt Securities | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	11,697,000,000		12,971,000,000
Other, Debt Securities | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	0		0
Other, Debt Securities | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	11,560,000,000		12,843,000,000
Other, Debt Securities | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	137,000,000		128,000,000
Other, Debt Securities | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities	0		0
Equity securities | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	88,944,000,000		110,699,000,000
Available-for-sale securities	2,610,000,000		2,771,000,000
Equity securities | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	86,358,000,000		106,898,000,000
Available-for-sale securities	2,610,000,000		2,733,000,000
Equity securities | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	1,547,000,000		2,687,000,000
Available-for-sale securities	0		38,000,000
Equity securities | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	1,039,000,000		1,114,000,000
Available-for-sale securities	0		0
Equity securities | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Available-for-sale securities	0		0
Physical commodities [Member] | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	11,941,000,000		16,173,000,000
Physical commodities [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	7,016,000,000		10,107,000,000
Physical commodities [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	4,909,000,000		6,066,000,000
Physical commodities [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	16,000,000		0
Physical commodities [Member] | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Other Debt and Equity Instruments [Member] | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	5,117,000,000		4,346,000,000
Other Debt and Equity Instruments [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Other Debt and Equity Instruments [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	4,012,000,000		3,483,000,000
Other Debt and Equity Instruments [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	1,105,000,000		863,000,000
Other Debt and Equity Instruments [Member] | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total assets measured at fair value on a recurring basis	113,800,000,000		119,400,000,000
Credit Derivative [Member] | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	73,751,000,000		74,983,000,000
Trading liabilities	64,385,000,000		70,656,000,000
Credit Derivative [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	4,382,000,000		1,242,000,000
Trading liabilities	3,823,000,000		1,094,000,000
Credit Derivative [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	1,327,501,000,000		1,640,806,000,000
Trading liabilities	1,310,451,000,000		1,620,025,000,000
Credit Derivative [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	17,429,000,000		22,233,000,000
Trading liabilities	17,845,000,000		20,340,000,000
Credit Derivative [Member] | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	(1,275,561,000,000)		(1,589,298,000,000)
Trading liabilities	(1,267,734,000,000)		(1,570,803,000,000)
Interest rate contract | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	31,697,000,000		39,205,000,000
Trading liabilities	18,416,000,000		24,906,000,000
Interest rate contract | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	2,875,000,000		476,000,000
Trading liabilities	2,266,000,000		490,000,000
Interest rate contract | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	963,223,000,000		1,295,474,000,000
Trading liabilities	932,906,000,000		1,256,934,000,000
Interest rate contract | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	5,114,000,000		6,617,000,000
Trading liabilities	3,013,000,000		3,295,000,000
Interest rate contract | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	(939,515,000,000)		(1,263,362,000,000)
Trading liabilities	(919,769,000,000)		(1,235,813,000,000)
Credit derivatives | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	2,364,000,000		1,735,000,000
Trading liabilities	2,611,000,000		2,504,000,000
Credit derivatives | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Trading liabilities	0		0
Credit derivatives | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	89,247,000,000		93,821,000,000
Trading liabilities	88,150,000,000		95,411,000,000
Credit derivatives | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	4,414,000,000		6,489,000,000
Trading liabilities	3,493,000,000		4,616,000,000
Credit derivatives | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	(91,297,000,000)		(98,575,000,000)
Trading liabilities	(89,032,000,000)		(97,523,000,000)
Foreign exchange | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	14,317,000,000		14,142,000,000
Trading liabilities	16,710,000,000		18,601,000,000
Foreign exchange | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	966,000,000		450,000,000
Trading liabilities	932,000,000		428,000,000
Foreign exchange | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	174,239,000,000		171,439,000,000
Trading liabilities	188,858,000,000		183,308,000,000
Foreign exchange | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	2,052,000,000		3,051,000,000
Trading liabilities	3,270,000,000		4,801,000,000
Foreign exchange | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	(162,940,000,000)		(160,798,000,000)
Trading liabilities	(176,350,000,000)		(169,936,000,000)
Equity | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	13,569,000,000		9,266,000,000
Trading liabilities	14,728,000,000		11,819,000,000
Equity | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	0		0
Trading liabilities	0		0
Equity | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	46,990,000,000		37,741,000,000
Trading liabilities	46,044,000,000		37,807,000,000
Equity | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	5,069,000,000		4,921,000,000
Trading liabilities	7,360,000,000		6,727,000,000
Equity | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	(38,490,000,000)		(33,396,000,000)
Trading liabilities	(38,676,000,000)		(32,715,000,000)
Commodity Contract | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	11,804,000,000		10,635,000,000
Trading liabilities	11,920,000,000		12,826,000,000
Commodity Contract | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	541,000,000		316,000,000
Trading liabilities	625,000,000		176,000,000
Commodity Contract | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	53,802,000,000		42,331,000,000
Trading liabilities	54,493,000,000		46,565,000,000
Commodity Contract | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	780,000,000		1,155,000,000
Trading liabilities	709,000,000		901,000,000
Commodity Contract | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets	(43,319,000,000)		(33,167,000,000)
Trading liabilities	(43,907,000,000)		(34,816,000,000)
Total other assets | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	4,444,000,000		4,766,000,000
Total other assets | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	432,000,000		253,000,000
Total other assets | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	10,785,000,000		11,439,000,000
Total other assets | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	0		0
Total other assets | Fair value | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	15,661,000,000		16,458,000,000
Private Equity Funds [Member] | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	7,655,000,000		7,759,000,000
Private Equity Funds [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	550,000,000		578,000,000
Private Equity Funds [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	0		0
Private Equity Funds [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	7,105,000,000		7,181,000,000
Private Equity Funds [Member] | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	0		0
All other assets [Member] | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	8,006,000,000		8,699,000,000
All other assets [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	3,894,000,000		4,188,000,000
All other assets [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	432,000,000		253,000,000
All other assets [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	3,680,000,000		4,258,000,000
All other assets [Member] | Fair Value, Measurements, Recurring [Member] | Netting adjustments [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Total other assets	0		0
Long Term Beneficial Interests | Fair value | Fair Value, Measurements, Recurring [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Beneficial interests issued by consolidated VIEs, at fair value	1,043,000,000		1,170,000,000
FairValueLevelThreeToLevelTwoTransfersAmount [Member] | Fair value | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Long-term debt				1,300,000,000
FairValueLevelThreeToLevelTwoTransfersAmount [Member] | Asset-backed securities | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading assets		1,300,000,000
FairValueLevelThreeToLevelTwoTransfersAmount [Member] | Collateralized loan obligations | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Available-for-sale securities		27,300,000,000
FairValueLevelThreeToLevelTwoTransfersAmount [Member] | Equity | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and liabilities measured at fair value on a recurring basis [Abstract]
Trading liabilities				$ 1,200,000,000