DERIVATIVES ACTIVITIES - Credit Derivatives (Details) $ in Millions	9 Months Ended
	Sep. 30, 2017 USD ($) agency	Dec. 31, 2016 USD ($)
Credit Risk Derivatives
Fair values, Receivable	$ 23,256	$ 24,821
Fair values, Payable	25,550	25,825
Notionals, Protection purchased	914,067	902,473
Notionals, Protection sold	872,574	859,420
Fair value of derivative in liability position	28,000	26,000
Fair value of collateral already posted	$ 25,000	26,000
Number of rating agencies | agency	3
Additional collateral to be posted	$ 1,200
Collateral to be segregated	300
Aggregate cash obligations and collateral requirements	1,500
Purchased
Credit Risk Derivatives
Fair values, Receivable	5,076	9,077
Fair values, Payable	20,616	17,110
Sold
Credit Risk Derivatives
Fair values, Receivable	18,180	15,744
Fair values, Payable	4,934	8,715
Within 1 year
Credit Risk Derivatives
Fair values, Receivable	2,520	4,113
Fair values, Payable	3,225	4,841
Notionals, Protection purchased	279,201	293,059
Notionals, Protection sold	267,863	287,262
From 1 to 5 years
Credit Risk Derivatives
Fair values, Receivable	17,459	17,735
Fair values, Payable	18,823	17,986
Notionals, Protection purchased	547,675	551,155
Notionals, Protection sold	522,437	523,371
After 5 years
Credit Risk Derivatives
Fair values, Receivable	3,277	2,973
Fair values, Payable	3,502	2,998
Notionals, Protection purchased	87,191	58,259
Notionals, Protection sold	82,274	48,787
Investment grade
Credit Risk Derivatives
Fair values, Receivable	13,045	9,605
Fair values, Payable	13,758	9,995
Notionals, Protection purchased	696,474	675,138
Notionals, Protection sold	665,764	648,247
Non-investment grade
Credit Risk Derivatives
Fair values, Receivable	10,211	15,216
Fair values, Payable	11,792	15,830
Notionals, Protection purchased	217,593	227,335
Notionals, Protection sold	206,810	211,173
Credit default swaps and options
Credit Risk Derivatives
Fair values, Receivable	23,013	24,502
Fair values, Payable	24,365	24,631
Notionals, Protection purchased	890,913	883,719
Notionals, Protection sold	862,753	852,900
Total return swaps and other
Credit Risk Derivatives
Fair values, Receivable	243	319
Fair values, Payable	1,185	1,194
Notionals, Protection purchased	23,154	18,754
Notionals, Protection sold	9,821	6,520
Banks
Credit Risk Derivatives
Fair values, Receivable	9,114	11,895
Fair values, Payable	8,454	10,930
Notionals, Protection purchased	320,482	407,992
Notionals, Protection sold	338,723	414,720
Broker-dealers
Credit Risk Derivatives
Fair values, Receivable	2,882	3,536
Fair values, Payable	2,805	3,952
Notionals, Protection purchased	89,352	115,013
Notionals, Protection sold	100,408	119,810
Non-financial
Credit Risk Derivatives
Fair values, Receivable	28	82
Fair values, Payable	93	99
Notionals, Protection purchased	2,154	4,014
Notionals, Protection sold	1,501	2,061
Insurance and other financial institutions
Credit Risk Derivatives
Fair values, Receivable	11,232	9,308
Fair values, Payable	14,198	10,844
Notionals, Protection purchased	502,079	375,454
Notionals, Protection sold	431,942	$ 322,829
Interest rate swaps
Credit Risk Derivatives
Cash proceeds received for assets derecognized	2,400
Fair value of derecognized assets	2,400
Fair value gross derivative assets	28
Trading derivatives, liability	$ 47