DERIVATIVES ACTIVITIES - Derivative Notionals (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Net Investment Hedging
Derivatives
Derivative notionals	$ 63,000,000	$ 1,825,000,000
Hedging instruments under ASC 815
Derivatives
Derivative notionals	270,947,000,000	227,616,000,000
Hedging instruments under ASC 815 | Interest rate contracts
Derivatives
Derivative notionals	186,553,000,000	151,428,000,000
Hedging instruments under ASC 815 | Interest rate swaps
Derivatives
Derivative notionals	186,553,000,000	151,331,000,000
Hedging instruments under ASC 815 | Interest rate futures and forwards
Derivatives
Derivative notionals	0	97,000,000
Hedging instruments under ASC 815 | Interest rate contract options | Written or Sold
Derivatives
Derivative notionals	0
Hedging instruments under ASC 815 | Interest rate contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Foreign exchange contracts
Derivatives
Derivative notionals	84,255,000,000	76,006,000,000
Hedging instruments under ASC 815 | Foreign exchange swaps
Derivatives
Derivative notionals	35,431,000,000	19,042,000,000
Hedging instruments under ASC 815 | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	38,100,000,000	56,964,000,000
Hedging instruments under ASC 815 | Foreign exchange contract options | Written or Sold
Derivatives
Derivative notionals	4,027,000,000	0
Hedging instruments under ASC 815 | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	6,697,000,000	0
Hedging instruments under ASC 815 | Equity contracts
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity swaps
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity futures and forwards
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity contract options | Written or Sold
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other contracts
Derivatives
Derivative notionals	139,000,000	182,000,000
Hedging instruments under ASC 815 | Commodity and other swaps
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other futures and forwards
Derivatives
Derivative notionals	139,000,000	182,000,000
Hedging instruments under ASC 815 | Commodity and other contracts | Written or Sold
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other contracts | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Credit derivatives
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Credit derivatives | Written or Sold
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Credit derivatives | Purchased
Derivatives
Derivative notionals	0	0
Other derivative instruments, Trading derivatives
Derivatives
Derivative notionals	52,139,112,000,000	45,753,242,000,000
Other derivative instruments, Trading derivatives | Interest rate contracts
Derivatives
Derivative notionals	34,446,912,000,000	31,699,124,000,000
Other derivative instruments, Trading derivatives | Interest rate swaps
Derivatives
Derivative notionals	20,878,378,000,000	19,145,250,000,000
Other derivative instruments, Trading derivatives | Interest rate futures and forwards
Derivatives
Derivative notionals	6,926,108,000,000	6,864,276,000,000
Other derivative instruments, Trading derivatives | Interest rate contract options | Written or Sold
Derivatives
Derivative notionals	3,446,771,000,000	2,921,070,000,000
Other derivative instruments, Trading derivatives | Interest rate contract options | Purchased
Derivatives
Derivative notionals	3,195,655,000,000	2,768,528,000,000
Other derivative instruments, Trading derivatives | Foreign exchange contracts
Derivatives
Derivative notionals	14,503,681,000,000	11,153,563,000,000
Other derivative instruments, Trading derivatives | Foreign exchange swaps
Derivatives
Derivative notionals	6,870,504,000,000	5,492,145,000,000
Other derivative instruments, Trading derivatives | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	4,658,973,000,000	3,251,132,000,000
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Written or Sold
Derivatives
Derivative notionals	1,466,308,000,000	1,194,325,000,000
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	1,507,896,000,000	1,215,961,000,000
Other derivative instruments, Trading derivatives | Equity contracts
Derivatives
Derivative notionals	1,023,929,000,000	800,572,000,000
Other derivative instruments, Trading derivatives | Equity swaps
Derivatives
Derivative notionals	219,056,000,000	192,366,000,000
Other derivative instruments, Trading derivatives | Equity futures and forwards
Derivatives
Derivative notionals	57,541,000,000	37,557,000,000
Other derivative instruments, Trading derivatives | Equity contract options | Written or Sold
Derivatives
Derivative notionals	410,746,000,000	304,579,000,000
Other derivative instruments, Trading derivatives | Equity contract options | Purchased
Derivatives
Derivative notionals	336,586,000,000	266,070,000,000
Other derivative instruments, Trading derivatives | Commodity and other contracts
Derivatives
Derivative notionals	391,248,000,000	357,560,000,000
Other derivative instruments, Trading derivatives | Commodity and other swaps
Derivatives
Derivative notionals	81,208,000,000	70,774,000,000
Other derivative instruments, Trading derivatives | Commodity and other futures and forwards
Derivatives
Derivative notionals	158,757,000,000	142,530,000,000
Other derivative instruments, Trading derivatives | Commodity and other contracts | Written or Sold
Derivatives
Derivative notionals	76,663,000,000	74,627,000,000
Other derivative instruments, Trading derivatives | Commodity and other contracts | Purchased
Derivatives
Derivative notionals	74,620,000,000	69,629,000,000
Other derivative instruments, Trading derivatives | Credit derivatives
Derivatives
Derivative notionals	1,773,342,000,000	1,742,423,000,000
Other derivative instruments, Trading derivatives | Credit derivatives | Written or Sold
Derivatives
Derivative notionals	872,476,000,000	859,420,000,000
Other derivative instruments, Trading derivatives | Credit derivatives | Purchased
Derivatives
Derivative notionals	900,866,000,000	883,003,000,000
Other derivative instruments, Management hedges
Derivatives
Derivative notionals	104,211,000,000	135,802,000,000
Other derivative instruments, Management hedges | Interest rate contracts
Derivatives
Derivative notionals	58,707,000,000	90,237,000,000
Other derivative instruments, Management hedges | Interest rate swaps
Derivatives
Derivative notionals	38,964,000,000	47,324,000,000
Other derivative instruments, Management hedges | Interest rate futures and forwards
Derivatives
Derivative notionals	13,504,000,000	30,834,000,000
Other derivative instruments, Management hedges | Interest rate contract options | Written or Sold
Derivatives
Derivative notionals	2,659,000,000	4,759,000,000
Other derivative instruments, Management hedges | Interest rate contract options | Purchased
Derivatives
Derivative notionals	3,580,000,000	7,320,000,000
Other derivative instruments, Management hedges | Foreign exchange contracts
Derivatives
Derivative notionals	32,205,000,000	26,095,000,000
Other derivative instruments, Management hedges | Foreign exchange swaps
Derivatives
Derivative notionals	27,052,000,000	22,676,000,000
Other derivative instruments, Management hedges | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	5,153,000,000	3,419,000,000
Other derivative instruments, Management hedges | Foreign exchange contract options | Written or Sold
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Equity contracts
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Equity swaps
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Equity futures and forwards
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Equity contract options | Written or Sold
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Equity contract options | Purchased
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Commodity and other contracts
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Commodity and other swaps
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Commodity and other futures and forwards
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Commodity and other contracts | Written or Sold
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Commodity and other contracts | Purchased
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Credit derivatives
Derivatives
Derivative notionals	13,299,000,000	19,470,000,000
Other derivative instruments, Management hedges | Credit derivatives | Written or Sold
Derivatives
Derivative notionals	98,000,000	0
Other derivative instruments, Management hedges | Credit derivatives | Purchased
Derivatives
Derivative notionals	$ 13,201,000,000	$ 19,470,000,000