DERIVATIVES ACTIVITIES - Derivative Notionals (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Net Investment Hedging
Derivatives
Derivative notionals	$ 2,229	$ 2,102
Hedging instruments under ASC 815 (SFAS 133)
Derivatives
Derivative notionals	274,913	263,763
Hedging instruments under ASC 815 (SFAS 133) | Interest rate contracts
Derivatives
Derivative notionals	176,364	166,576
Hedging instruments under ASC 815 (SFAS 133) | Interest rate swaps
Derivatives
Derivative notionals	176,364	166,576
Hedging instruments under ASC 815 (SFAS 133) | Interest rate futures and forwards
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 (SFAS 133) | Interest rate contract options | Written or Sold
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 (SFAS 133) | Interest rate contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 (SFAS 133) | Foreign exchange contracts
Derivatives
Derivative notionals	97,776	96,398
Hedging instruments under ASC 815 (SFAS 133) | Foreign exchange swaps
Derivatives
Derivative notionals	22,922	23,007
Hedging instruments under ASC 815 (SFAS 133) | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	74,594	72,124
Hedging instruments under ASC 815 (SFAS 133) | Foreign exchange contract options | Written or Sold
Derivatives
Derivative notionals	0	448
Hedging instruments under ASC 815 (SFAS 133) | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	260	819
Hedging instruments under ASC 815 (SFAS 133) | Equity contracts
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 (SFAS 133) | Equity swaps
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 (SFAS 133) | Equity futures and forwards
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 (SFAS 133) | Equity contract options | Written or Sold
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 (SFAS 133) | Equity contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 (SFAS 133) | Commodity and other contracts
Derivatives
Derivative notionals	773	789
Hedging instruments under ASC 815 (SFAS 133) | Commodity and other swaps
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 (SFAS 133) | Commodity and other futures and forwards
Derivatives
Derivative notionals	773	789
Hedging instruments under ASC 815 (SFAS 133) | Commodity and other contracts | Written or Sold
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 (SFAS 133) | Commodity and other contracts | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 (SFAS 133) | Credit derivatives
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 (SFAS 133) | Credit derivatives | Written or Sold
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 (SFAS 133) | Credit derivatives | Purchased
Derivatives
Derivative notionals	0	0
Other derivative instruments, Trading derivatives
Derivatives
Derivative notionals	52,494,266	47,612,050
Other derivative instruments, Trading derivatives | Interest rate contracts
Derivatives
Derivative notionals	38,039,672	34,998,356
Other derivative instruments, Trading derivatives | Interest rate swaps
Derivatives
Derivative notionals	24,947,131	22,208,794
Other derivative instruments, Trading derivatives | Interest rate futures and forwards
Derivatives
Derivative notionals	6,680,954	6,868,340
Other derivative instruments, Trading derivatives | Interest rate contract options | Written or Sold
Derivatives
Derivative notionals	3,292,207	3,033,617
Other derivative instruments, Trading derivatives | Interest rate contract options | Purchased
Derivatives
Derivative notionals	3,119,380	2,887,605
Other derivative instruments, Trading derivatives | Foreign exchange contracts
Derivatives
Derivative notionals	11,511,741	9,586,816
Other derivative instruments, Trading derivatives | Foreign exchange swaps
Derivatives
Derivative notionals	5,069,925	4,765,687
Other derivative instruments, Trading derivatives | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	3,475,559	2,563,649
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Written or Sold
Derivatives
Derivative notionals	1,465,953	1,125,664
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	1,500,304	1,131,816
Other derivative instruments, Trading derivatives | Equity contracts
Derivatives
Derivative notionals	566,715	778,636
Other derivative instruments, Trading derivatives | Equity swaps
Derivatives
Derivative notionals	179,249	180,963
Other derivative instruments, Trading derivatives | Equity futures and forwards
Derivatives
Derivative notionals	37,778	33,735
Other derivative instruments, Trading derivatives | Equity contract options | Written or Sold
Derivatives
Derivative notionals	193,117	298,876
Other derivative instruments, Trading derivatives | Equity contract options | Purchased
Derivatives
Derivative notionals	156,571	265,062
Other derivative instruments, Trading derivatives | Commodity and other contracts
Derivatives
Derivative notionals	320,562	315,734
Other derivative instruments, Trading derivatives | Commodity and other swaps
Derivatives
Derivative notionals	64,768	70,561
Other derivative instruments, Trading derivatives | Commodity and other futures and forwards
Derivatives
Derivative notionals	115,817	106,474
Other derivative instruments, Trading derivatives | Commodity and other contracts | Written or Sold
Derivatives
Derivative notionals	72,600	72,648
Other derivative instruments, Trading derivatives | Commodity and other contracts | Purchased
Derivatives
Derivative notionals	67,377	66,051
Other derivative instruments, Trading derivatives | Credit derivatives
Derivatives
Derivative notionals	2,055,576	1,932,508
Other derivative instruments, Trading derivatives | Credit derivatives | Written or Sold
Derivatives
Derivative notionals	1,006,498	950,922
Other derivative instruments, Trading derivatives | Credit derivatives | Purchased
Derivatives
Derivative notionals	1,049,078	981,586
Other derivative instruments, Management hedges
Derivatives
Derivative notionals	124,105	125,193
Other derivative instruments, Management hedges | Interest rate contracts
Derivatives
Derivative notionals	71,984	74,571
Other derivative instruments, Management hedges | Interest rate swaps
Derivatives
Derivative notionals	36,223	28,969
Other derivative instruments, Management hedges | Interest rate futures and forwards
Derivatives
Derivative notionals	29,459	38,421
Other derivative instruments, Management hedges | Interest rate contract options | Written or Sold
Derivatives
Derivative notionals	2,642	2,606
Other derivative instruments, Management hedges | Interest rate contract options | Purchased
Derivatives
Derivative notionals	3,660	4,575
Other derivative instruments, Management hedges | Foreign exchange contracts
Derivatives
Derivative notionals	25,802	26,994
Other derivative instruments, Management hedges | Foreign exchange swaps
Derivatives
Derivative notionals	21,944	23,960
Other derivative instruments, Management hedges | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	3,858	3,034
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	26,319	23,628
Other derivative instruments, Management hedges | Credit derivatives | Written or Sold
Derivatives
Derivative notionals	0	0
Other derivative instruments, Management hedges | Credit derivatives | Purchased
Derivatives
Derivative notionals	$ 26,319	$ 23,628