DERIVATIVES ACTIVITIES - Derivative Mark-to-Market (MTM) Receivables/Payables (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting of cash collateral received	$ (38,743)	$ (45,912)
Less: Netting of cash collateral paid	(42,570)	(49,811)
Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Cash collateral received, gross	56	61
Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	508,731	617,477
Cash collateral paid, net of amount used to offset derivative liabilities	12,540	11,188
Less: Netting agreements to assets	(424,492)	(519,000)
Less: Netting of cash collateral received	(38,743)	(45,912)
Total trading account derivatives, assets	58,036	63,753
Less: Cash collateral received	(657)	(819)
Less: Non-cash collateral received	(11,359)	(11,767)
Total Net receivables	46,020	51,167
Cash collateral paid, gross	55,110	60,999
Does not meet applicable offsetting guidance, assets	4,000	7,000
Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to assets	(321,000)	(383,000)
Less: Netting agreements to liabilities		(383,000)
Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to assets	(95,000)	(128,000)
Less: Netting agreements to liabilities		(128,000)
Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to assets	(8,000)	(8,000)
Less: Netting agreements to liabilities		(8,000)
Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	503,772	609,507
Cash collateral received, net of amount used to offset derivative assets	14,227	15,731
Less: Netting agreements to liabilities	(424,492)	(519,000)
Less: Netting of cash collateral paid	(42,570)	(49,811)
Total derivative liabilities	50,937	56,427
Less: Cash collateral paid	(55)	(19)
Less: Non-cash collateral paid	(8,039)	(5,883)
Total Net payables	42,843	50,525
Cash collateral received, gross	52,970	61,643
Does not meet applicable offsetting guidance, liabilities	7,000	9,000
Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to liabilities	(321,000)
Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to liabilities	(95,000)
Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to liabilities	(8,000)
Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,935	3,392
Cash collateral paid, net of amount used to offset derivative liabilities	0	8
Less: Netting agreements to assets	0	0
Less: Netting of cash collateral received	(993)	(1,345)
Total trading account derivatives, assets	942	2,055
Less: Cash collateral received	0	0
Less: Non-cash collateral received	(295)	(530)
Total Net receivables	647	1,525
Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	966	1,551
Cash collateral received, net of amount used to offset derivative assets	43	1
Less: Netting agreements to liabilities	0	0
Less: Netting of cash collateral received	(56)	(53)
Less: Netting of cash collateral paid	(56)	(53)
Total derivative liabilities	953	1,499
Less: Cash collateral paid	0	0
Less: Non-cash collateral paid	0	0
Total Net payables	953	1,499
Cash collateral received, gross	1,036	1,346
Derivative instruments designated as ASC 815 hedges | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	5,477	6,740
Derivative instruments designated as ASC 815 hedges | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	2,823	2,718
Derivative instruments designated as ASC 815 hedges | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,715	2,721
Derivative instruments designated as ASC 815 hedges | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	477	749
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	4,419	4,246
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	4,089	716
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	330	3,530
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	2,028	2,325
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	271	171
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	1,757	2,154
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,304	1,974
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,270	1,927
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Other assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	34	47
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	93	104
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	20	22
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Other liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	73	82
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,058	2,494
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,058	2,494
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	795	393
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	795	393
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	411	747
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	411	747
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	384	645
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	384	645
Derivatives instruments not designated as ASC 815 hedges | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	503,254	610,737
Derivatives instruments not designated as ASC 815 hedges | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	500,949	606,789
Derivatives instruments not designated as ASC 815 hedges | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	220	671
Derivatives instruments not designated as ASC 815 hedges | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	489	802
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	300,281	365,079
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	212,052	244,072
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	88,092	120,920
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	137	87
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	288,166	352,436
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	193,609	221,534
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	94,441	130,855
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	116	47
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	139	465
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	38	225
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Other assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	101	240
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Other assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	139	354
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	1	5
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Other liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	138	349
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Other liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	144,757	183,168
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	142,009	182,659
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	2,667	482
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	81	27
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	146,142	187,368
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	143,455	186,867
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	2,611	470
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	76	31
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Other assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Other assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	60
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	60
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Other liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Other liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	24,168	24,110
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	16,262	15,625
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	21	1
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	7,885	8,484
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	29,004	26,516
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	20,994	19,119
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	12	21
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	7,998	7,376
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Other assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Other assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Other liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Other liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	10,148	13,765
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	9,506	13,046
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Trading accounts assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	642	719
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	12,541	15,032
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	11,894	14,234
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	647	798
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Other assets | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	0	0
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives instruments not designated as ASC 815 hedges | Commodity and other contracts | Other liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	0	0
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	23,900	24,615
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts assets | Purchased
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	5,801	8,871
Derivative payables		16,722
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts assets | Sold
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	18,099	15,744
Derivative payables		8,715
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	16,325	19,033
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	7,575	5,582
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	25,096	25,437
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts liabilities | Purchased
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	19,400
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts liabilities | Sold
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	5,696
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	17,190	19,563
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	7,906	5,874
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	81	206
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Other assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	49	159
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Other assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	32	47
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	350	388
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Other liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	58	78
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Other liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	$ 292	$ 310