DERIVATIVES ACTIVITIES - Derivative Mark-to-Market (MTM) Receivables/Payables (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting of cash collateral received	$ (37,876)	$ (45,912)
Less: Netting of cash collateral paid	(32,390)	(49,811)
Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Cash collateral received, gross	17	61
Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	405,239	617,477
Cash collateral paid, net of amount used to offset derivative liabilities	13,991	11,188
Less: Netting agreements to assets	(325,424)	(519,000)
Less: Netting of cash collateral received	(37,876)	(45,912)
Total trading account derivatives, assets	55,930	63,753
Less: Cash collateral received	(861)	(819)
Less: Non-cash collateral received	(11,864)	(11,767)
Total Net receivables	43,205	51,167
Cash collateral paid, gross	46,381	60,999
Does not meet applicable offsetting guidance, assets	5,000	7,000
Trading accounts assets | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to assets	(301,000)	(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	(15,000)	(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	(9,000)	(8,000)
Less: Netting agreements to liabilities		(8,000)
Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	393,830	609,507
Cash collateral received, net of amount used to offset derivative assets	15,848	15,731
Less: Netting agreements to liabilities	(325,424)	(519,000)
Less: Netting of cash collateral paid	(32,390)	(49,811)
Total derivative liabilities	51,864	56,427
Less: Cash collateral paid	(61)	(19)
Less: Non-cash collateral paid	(9,798)	(5,883)
Total Net payables	42,005	50,525
Cash collateral received, gross	53,724	61,643
Does not meet applicable offsetting guidance, liabilities	6,000	9,000
Trading accounts liabilities | Over-the-counter
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to liabilities	(301,000)
Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to liabilities	(15,000)
Trading accounts liabilities | Exchange traded
Derivative Mark-to-Market (MTM) Receivables/Payables
Less: Netting agreements to liabilities	(9,000)
Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	2,250	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	(1,005)	(1,345)
Total trading account derivatives, assets	1,245	2,055
Less: Cash collateral received	0	0
Less: Non-cash collateral received	(294)	(530)
Total Net receivables	951	1,525
Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	717	1,551
Cash collateral received, net of amount used to offset derivative assets	9	1
Less: Netting agreements to liabilities	0	0
Less: Netting of cash collateral received	(17)	(53)
Less: Netting of cash collateral paid	(17)	(53)
Total derivative liabilities	709	1,499
Less: Cash collateral paid	0	0
Less: Non-cash collateral paid	0	0
Total Net payables	709	1,499
Cash collateral received, gross	1,014	1,346
Derivative instruments designated as ASC 815 hedges | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,405	6,740
Derivative instruments designated as ASC 815 hedges | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	812	2,718
Derivative instruments designated as ASC 815 hedges | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	2,097	2,721
Derivative instruments designated as ASC 815 hedges | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	246	749
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	469	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	440	716
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	29	3,530
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	136	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	107	171
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	29	2,154
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	1,326	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	1,291	1,927
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Other assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	35	47
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	99	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	30	22
Derivative instruments designated as ASC 815 hedges | Interest rate contracts | Other liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	69	82
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	936	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	936	2,494
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	676	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	676	393
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	771	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	771	747
Derivative instruments designated as ASC 815 hedges | Foreign exchange contracts | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	147	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	147	645
Derivatives instruments not designated as ASC 815 hedges | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	403,834	610,737
Derivatives instruments not designated as ASC 815 hedges | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	393,018	606,789
Derivatives instruments not designated as ASC 815 hedges | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	153	671
Derivatives instruments not designated as ASC 815 hedges | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	471	802
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	207,513	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	200,554	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	6,843	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	116	87
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	187,613	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	179,000	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	8,520	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	93	47
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	108	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	35	225
Derivatives instruments not designated as ASC 815 hedges | Interest rate contracts | Other assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	73	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	106	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	105	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	133,637	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	130,399	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	3,180	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	58	27
Derivatives instruments not designated as ASC 815 hedges | Foreign exchange contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	132,460	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	129,096	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	3,312	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	52	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	27,284	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	18,736	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	16	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	8,532	8,484
Derivatives instruments not designated as ASC 815 hedges | Equity contracts | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	32,516	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	24,317	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	20	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	8,179	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	12,189	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	11,444	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	745	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	15,244	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	14,541	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	703	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	23,211	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	5,076	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	18,180	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	15,169	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	8,042	5,582
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	25,185	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	20,616
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Trading accounts liabilities | Sold
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	4,934
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	15,592	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	9,593	5,874
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Other assets
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	45	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	23	159
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Other assets | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative receivables	22	47
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Other liabilities
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	365	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	68	78
Derivatives instruments not designated as ASC 815 hedges | Credit derivatives | Other liabilities | Cleared
Derivative Mark-to-Market (MTM) Receivables/Payables
Derivative payables	$ 297	$ 310