DERIVATIVES ACTIVITIES - Credit Derivatives (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($) agency	Dec. 31, 2016 USD ($)
Credit Risk Derivatives
Fair values, Receivable	$ 23,394	$ 24,821
Fair Values, Payable	25,098	25,825
Notionals, Protection purchased	912,606	902,473
Notionals, Protection sold	876,791	859,420
Fair value of derivative in liability position	29,000	26,000
Fair value of collateral already posted	$ 26,000	26,000
Number of rating agencies | agency	3
Additional collateral to be posted	$ 1,100
Collateral to be segregated	300
Aggregate cash obligations and collateral requirements	1,400
Purchased
Credit Risk Derivatives
Fair values, Receivable	6,384	9,077
Fair Values, Payable	18,879	17,110
Sold
Credit Risk Derivatives
Fair values, Receivable	17,010	15,744
Fair Values, Payable	6,219	8,715
Within 1 year
Credit Risk Derivatives
Fair values, Receivable	3,008	4,113
Fair Values, Payable	4,108	4,841
Notionals, Protection purchased	304,227	293,059
Notionals, Protection sold	296,731	287,262
From 1 to 5 years
Credit Risk Derivatives
Fair values, Receivable	16,894	17,735
Fair Values, Payable	17,187	17,986
Notionals, Protection purchased	532,809	551,155
Notionals, Protection sold	511,054	523,371
After 5 years
Credit Risk Derivatives
Fair values, Receivable	3,492	2,973
Fair Values, Payable	3,803	2,998
Notionals, Protection purchased	75,570	58,259
Notionals, Protection sold	69,006	48,787
Investment grade
Credit Risk Derivatives
Fair values, Receivable	9,951	9,605
Fair Values, Payable	10,142	9,995
Notionals, Protection purchased	691,002	675,138
Notionals, Protection sold	669,241	648,247
Non-investment grade
Credit Risk Derivatives
Fair values, Receivable	13,443	15,216
Fair Values, Payable	14,956	15,830
Notionals, Protection purchased	221,604	227,335
Notionals, Protection sold	207,550	211,173
Credit default swaps and options
Credit Risk Derivatives
Fair values, Receivable	23,145	24,502
Fair Values, Payable	23,096	24,631
Notionals, Protection purchased	889,829	883,719
Notionals, Protection sold	868,748	852,900
Total return swaps and other
Credit Risk Derivatives
Fair values, Receivable	249	319
Fair Values, Payable	2,002	1,194
Notionals, Protection purchased	22,777	18,754
Notionals, Protection sold	8,043	6,520
Banks
Credit Risk Derivatives
Fair values, Receivable	10,428	11,895
Fair Values, Payable	9,483	10,930
Notionals, Protection purchased	383,466	407,992
Notionals, Protection sold	393,864	414,720
Broker-dealers
Credit Risk Derivatives
Fair values, Receivable	3,297	3,536
Fair Values, Payable	3,587	3,952
Notionals, Protection purchased	107,767	115,013
Notionals, Protection sold	116,589	119,810
Non-financial
Credit Risk Derivatives
Fair values, Receivable	80	82
Fair Values, Payable	187	99
Notionals, Protection purchased	3,164	4,014
Notionals, Protection sold	1,430	2,061
Insurance and other financial institutions
Credit Risk Derivatives
Fair values, Receivable	9,589	9,308
Fair Values, Payable	11,841	10,844
Notionals, Protection purchased	418,209	375,454
Notionals, Protection sold	364,908	$ 322,829
Interest rate swaps
Credit Risk Derivatives
Cash proceeds received for assets derecognized	1,500
Fair value of derecognized assets	1,500
Fair value gross derivative assets	29
Trading derivatives, liability	$ 6