FAIR VALUE MEASUREMENT - Items Measured at Fair Value on a Recurring Basis (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell, selected portfolios of securities purchased under agreements to resell, Netting	$ (53,365,000,000)	$ (56,339,000,000)
Trading account assets	302,983,000,000	296,786,000,000
Netting of cash collateral received	(53,848,000,000)	(47,625,000,000)
Investments	326,815,000,000	333,443,000,000
Loans	6,575,000,000	5,901,000,000
Mortgage servicing rights (MSRs)	1,685,000,000	1,845,000,000
Liabilities, Fair Value Disclosure [Abstract]
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Netting	(53,365,000,000)	(56,339,000,000)
Netting of cash collateral paid	(51,292,000,000)	(47,769,000,000)
Assets transferred from Level 1 to Level 2	600,000,000	4,100,000,000
Assets transferred from Level 2 to Level 1	1,800,000,000	4,200,000,000
Liabilities transferred from Level 1 to Level 2		1,400,000,000
Liabilities transferred from Level 2 to Level 1	200,000,000
Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	26,048,000,000	27,053,000,000
Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,832,000,000	4,343,000,000
Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	34,184,000,000	36,234,000,000
U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	23,608,000,000	20,474,000,000
State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,796,000,000	3,402,000,000
Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	69,417,000,000	64,937,000,000
Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	25,163,000,000	27,797,000,000
Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	57,536,000,000	57,846,000,000
Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	4,783,000,000	4,546,000,000
Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	12,915,000,000	13,593,000,000
Recurring
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	178,462,000,000	191,320,000,000
Federal funds sold and securities borrowed or purchased under agreements to resell, selected portfolios of securities purchased under agreements to resell, Netting	(42,568,000,000)	(47,129,000,000)
Federal funds sold and securities borrowed or purchased under agreements to resell, selected portfolios of securities purchased under agreements to resell	135,894,000,000	144,191,000,000
Investments	297,809,000,000	302,901,000,000
Loans	6,575,000,000	5,901,000,000
Mortgage servicing rights (MSRs)	1,685,000,000	1,845,000,000
Assets before netting	1,632,061,000,000	1,633,109,000,000
Total assets, Netting	(878,179,000,000)	(873,723,000,000)
Total assets	753,882,000,000	759,386,000,000
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	1,650,000,000	1,684,000,000
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Gross	76,793,000,000	83,854,000,000
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Netting	(42,568,000,000)	(47,129,000,000)
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase	34,225,000,000	36,725,000,000
Securities sold, not yet purchased	65,243,000,000	70,944,000,000
Short-term borrowings	926,000,000	1,496,000,000
Long-term debt, at fair value	25,409,000,000	26,180,000,000
Total liabilities, Gross	1,080,145,000,000	1,078,988,000,000
Total liabilities, Netting	(873,473,000,000)	(872,091,000,000)
Total liabilities	206,672,000,000	206,897,000,000
Recurring | Trading derivatives liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	897,702,000,000	883,193,000,000
Cash collateral received	10,398,000,000	9,846,000,000
Total trading derivatives and cash collateral, liability	908,100,000,000	893,039,000,000
Netting agreements	(779,613,000,000)	(777,178,000,000)
Netting of cash collateral paid	(51,292,000,000)	(47,769,000,000)
Netting, Liabilities, total of netting agreements and cash collateral received	(830,905,000,000)	(824,947,000,000)
Total derivative liabilities	77,195,000,000	68,092,000,000
Cash collateral received, gross	64,246,000,000	57,471,000,000
Recurring | Trading derivatives liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	622,573,000,000	622,282,000,000
Recurring | Trading derivatives liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	180,094,000,000	158,826,000,000
Recurring | Trading derivatives liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	32,630,000,000	32,469,000,000
Recurring | Trading derivatives liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	24,019,000,000	26,186,000,000
Recurring | Trading derivatives liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	38,386,000,000	43,430,000,000
Recurring | Non-trading derivatives and other financial liabilities
Assets, Fair Value Disclosure [Abstract]
Netting of cash collateral received		(1,791,000,000)
Cash collateral paid, gross		138,000,000
Liabilities, Fair Value Disclosure [Abstract]
Cash collateral received	56,000,000	7,000,000
Netting of cash collateral paid		(15,000,000)
Netting, Liabilities, total of netting agreements and cash collateral received	0
Other liabilities, gross	1,968,000,000	1,784,000,000
Non-trading derivatives and other financial liabilities measured on a recurring basis, gross	2,024,000,000	1,791,000,000
Total other assets and cash collateral, gross	2,024,000,000	1,776,000,000
Cash collateral received, gross	2,206,000,000	1,798,000,000
Recurring | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	26,048,000,000	27,053,000,000
Investments	39,084,000,000	36,091,000,000
Recurring | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	4,304,000,000	4,838,000,000
Investments	7,276,000,000	8,363,000,000
Recurring | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,832,000,000	4,343,000,000
Investments	507,000,000	554,000,000
Recurring | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	34,184,000,000	36,234,000,000
Investments	46,867,000,000	45,008,000,000
Recurring | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	23,608,000,000	20,474,000,000
Investments	121,359,000,000	123,690,000,000
Recurring | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,796,000,000	3,402,000,000
Investments	12,245,000,000	12,699,000,000
Recurring | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	69,417,000,000	64,937,000,000
Investments	87,059,000,000	90,697,000,000
Recurring | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	25,163,000,000	27,797,000,000
Investments	14,554,000,000	12,157,000,000
Recurring | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	57,536,000,000	57,846,000,000
Investments	990,000,000	2,725,000,000
Recurring | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	4,783,000,000	4,546,000,000
Investments	11,504,000,000	12,506,000,000
Recurring | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	12,915,000,000	13,593,000,000
Investments	661,000,000	661,000,000
Recurring | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	2,570,000,000	2,758,000,000
Recurring | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	897,772,000,000	886,237,000,000
Gross cash collateral paid	7,270,000,000	6,523,000,000
Trading derivative, asset, gross net cash collateral paid	905,042,000,000	892,760,000,000
Less: Netting agreements to assets	(779,613,000,000)	(777,178,000,000)
Netting of cash collateral received	(53,848,000,000)	(47,625,000,000)
Netting, Assets, total of netting agreements and cash collateral received	(833,461,000,000)	(824,803,000,000)
Trading derivatives	71,581,000,000	67,957,000,000
Cash collateral paid, gross	58,562,000,000	54,292,000,000
Recurring | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	639,982,000,000	638,453,000,000
Recurring | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	176,269,000,000	155,994,000,000
Recurring | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	24,275,000,000	24,752,000,000
Recurring | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	19,023,000,000	23,520,000,000
Recurring | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	38,223,000,000	43,518,000,000
Recurring | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Netting of cash collateral received	(2,150,000,000)	(1,791,000,000)
Netting, Assets, total of netting agreements and cash collateral received	(2,150,000,000)	(1,791,000,000)
Other assets, gross	11,057,000,000	9,430,000,000
Cash collateral paid, gross	29,000,000	123,000,000
Total other assets and cash collateral, gross	11,086,000,000	9,553,000,000
Other assets	8,936,000,000	7,762,000,000
Recurring | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	231,402,000,000	228,829,000,000
Recurring | Level 1
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	0	0
Investments	150,529,000,000	151,499,000,000
Loans	0	0
Mortgage servicing rights (MSRs)	0	0
Assets before netting	266,384,000,000	261,637,000,000
Total as a percentage of gross assets	16.40%	16.10%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	0	0
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Gross	0	0
Securities sold, not yet purchased	50,368,000,000	59,463,000,000
Short-term borrowings	0	0
Long-term debt, at fair value	0	0
Total liabilities, Gross	53,663,000,000	63,164,000,000
Total as a percentage of gross liabilities	5.00%	5.90%
Recurring | Level 1 | Trading derivatives liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	3,295,000,000	3,701,000,000
Recurring | Level 1 | Trading derivatives liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	57,000,000	77,000,000
Recurring | Level 1 | Trading derivatives liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	5,000,000	0
Recurring | Level 1 | Trading derivatives liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,718,000,000	2,955,000,000
Recurring | Level 1 | Trading derivatives liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	515,000,000	669,000,000
Recurring | Level 1 | Trading derivatives liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	0	0
Recurring | Level 1 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	0	0
Recurring | Level 1 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Recurring | Level 1 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Recurring | Level 1 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Other assets, gross		0
Recurring | Level 1 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Recurring | Level 1 | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	19,680,000,000	15,991,000,000
Investments	112,018,000,000	110,710,000,000
Recurring | Level 1 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Recurring | Level 1 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	41,548,000,000	37,995,000,000
Investments	36,262,000,000	37,280,000,000
Recurring | Level 1 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	595,000,000	1,337,000,000
Investments	1,842,000,000	1,739,000,000
Recurring | Level 1 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	50,782,000,000	51,346,000,000
Investments	407,000,000	1,770,000,000
Recurring | Level 1 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Recurring | Level 1 | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	0	0
Recurring | Level 1 | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	0	0
Recurring | Level 1 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	3,056,000,000	3,469,000,000
Recurring | Level 1 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	78,000,000	74,000,000
Recurring | Level 1 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	1,000,000	0
Recurring | Level 1 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,502,000,000	2,748,000,000
Recurring | Level 1 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	475,000,000	647,000,000
Recurring | Level 1 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	0	0
Recurring | Level 1 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	194,000,000	0
Recurring | Level 1 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	112,605,000,000	106,669,000,000
Recurring | Level 2
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	174,440,000,000	187,922,000,000
Investments	140,466,000,000	144,064,000,000
Loans	2,669,000,000	2,793,000,000
Mortgage servicing rights (MSRs)	0	0
Assets before netting	1,315,813,000,000	1,322,433,000,000
Total as a percentage of gross assets	81.00%	81.30%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	1,185,000,000	1,198,000,000
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Gross	75,733,000,000	82,811,000,000
Securities sold, not yet purchased	14,652,000,000	11,057,000,000
Short-term borrowings	806,000,000	1,152,000,000
Long-term debt, at fair value	18,213,000,000	18,890,000,000
Total liabilities, Gross	993,332,000,000	982,447,000,000
Total as a percentage of gross liabilities	92.90%	91.90%
Recurring | Level 2 | Trading derivatives liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	880,783,000,000	865,562,000,000
Recurring | Level 2 | Trading derivatives liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	618,464,000,000	617,933,000,000
Recurring | Level 2 | Trading derivatives liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	179,226,000,000	158,354,000,000
Recurring | Level 2 | Trading derivatives liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	27,084,000,000	26,616,000,000
Recurring | Level 2 | Trading derivatives liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	20,820,000,000	22,872,000,000
Recurring | Level 2 | Trading derivatives liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	35,189,000,000	39,787,000,000
Recurring | Level 2 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	1,960,000,000	1,777,000,000
Recurring | Level 2 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	25,230,000,000	25,968,000,000
Investments	39,014,000,000	36,053,000,000
Recurring | Level 2 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	2,174,000,000	2,158,000,000
Investments	7,266,000,000	8,355,000,000
Recurring | Level 2 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,233,000,000	3,903,000,000
Investments	505,000,000	553,000,000
Recurring | Level 2 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	30,637,000,000	32,029,000,000
Investments	46,785,000,000	44,961,000,000
Recurring | Level 2 | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,928,000,000	4,483,000,000
Investments	9,336,000,000	12,974,000,000
Recurring | Level 2 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,549,000,000	3,161,000,000
Investments	9,998,000,000	10,519,000,000
Recurring | Level 2 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	27,754,000,000	26,736,000,000
Investments	50,222,000,000	52,739,000,000
Recurring | Level 2 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	23,801,000,000	25,640,000,000
Investments	12,128,000,000	9,746,000,000
Recurring | Level 2 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	4,156,000,000	4,281,000,000
Investments	64,000,000	274,000,000
Recurring | Level 2 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,230,000,000	1,252,000,000
Investments	10,987,000,000	11,957,000,000
Recurring | Level 2 | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	8,522,000,000	9,221,000,000
Investments	661,000,000	661,000,000
Recurring | Level 2 | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	285,000,000	233,000,000
Recurring | Level 2 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	883,946,000,000	871,499,000,000
Recurring | Level 2 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	636,186,000,000	634,318,000,000
Recurring | Level 2 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	174,759,000,000	154,744,000,000
Recurring | Level 2 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	19,719,000,000	19,969,000,000
Recurring | Level 2 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	17,593,000,000	21,850,000,000
Recurring | Level 2 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	35,689,000,000	40,618,000,000
Recurring | Level 2 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	10,715,000,000	9,352,000,000
Recurring | Level 2 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	103,577,000,000	106,803,000,000
Recurring | Level 3
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	4,022,000,000	3,398,000,000
Investments	6,814,000,000	7,338,000,000
Loans	3,906,000,000	3,108,000,000
Mortgage servicing rights (MSRs)	1,685,000,000	1,845,000,000
Assets before netting	42,565,000,000	42,393,000,000
Total as a percentage of gross assets	2.60%	2.60%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	465,000,000	486,000,000
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Gross	1,060,000,000	1,043,000,000
Securities sold, not yet purchased	223,000,000	424,000,000
Short-term borrowings	120,000,000	344,000,000
Long-term debt, at fair value	7,196,000,000	7,290,000,000
Total liabilities, Gross	22,696,000,000	23,524,000,000
Total as a percentage of gross liabilities	2.10%	2.20%
Recurring | Level 3 | Trading derivatives liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	13,624,000,000	13,930,000,000
Recurring | Level 3 | Trading derivatives liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	4,052,000,000	4,272,000,000
Recurring | Level 3 | Trading derivatives liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	863,000,000	472,000,000
Recurring | Level 3 | Trading derivatives liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,828,000,000	2,898,000,000
Recurring | Level 3 | Trading derivatives liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,684,000,000	2,645,000,000
Recurring | Level 3 | Trading derivatives liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	3,197,000,000	3,643,000,000
Recurring | Level 3 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	8,000,000	7,000,000
Recurring | Level 3 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	818,000,000	1,085,000,000
Investments	70,000,000	38,000,000
Recurring | Level 3 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	2,130,000,000	2,680,000,000
Investments	10,000,000	8,000,000
Recurring | Level 3 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	599,000,000	440,000,000
Investments	2,000,000	1,000,000
Recurring | Level 3 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,547,000,000	4,205,000,000
Investments	82,000,000	47,000,000
Recurring | Level 3 | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0
Investments	5,000,000	6,000,000
Recurring | Level 3 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	247,000,000	241,000,000
Investments	2,247,000,000	2,180,000,000
Recurring | Level 3 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	115,000,000	206,000,000
Investments	575,000,000	678,000,000
Recurring | Level 3 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	767,000,000	820,000,000
Investments	584,000,000	672,000,000
Recurring | Level 3 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	2,598,000,000	2,219,000,000
Investments	519,000,000	681,000,000
Recurring | Level 3 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,553,000,000	3,294,000,000
Investments	517,000,000	549,000,000
Recurring | Level 3 | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	4,393,000,000	4,372,000,000
Investments	0	0
Recurring | Level 3 | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	2,285,000,000	2,525,000,000
Recurring | Level 3 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	10,770,000,000	11,269,000,000
Recurring | Level 3 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	3,718,000,000	4,061,000,000
Recurring | Level 3 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	1,509,000,000	1,250,000,000
Recurring | Level 3 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,054,000,000	2,035,000,000
Recurring | Level 3 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	955,000,000	1,023,000,000
Recurring | Level 3 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,534,000,000	2,900,000,000
Recurring | Level 3 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	148,000,000	78,000,000
Recurring | Level 3 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	$ 15,220,000,000	$ 15,357,000,000