COMMISSIONS AND FEES (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commissions and fees
Card fees amortization period		12 months
Total commissions and fees	[1]	$ 12,939	$ 11,938	$ 14,485
Investment banking
Commissions and fees
Total commissions and fees		3,613	2,847	3,423
Trading-related
Commissions and fees
Total commissions and fees		3,015	2,799	3,138
Trade and securities services
Commissions and fees
Total commissions and fees		1,632	1,564	1,735
Credit cards and bank cards
Commissions and fees
Total commissions and fees		1,510	1,324	1,786
Corporate finance
Commissions and fees
Total commissions and fees		713	686	493
Other consumer
Commissions and fees
Total commissions and fees		703	659	685
Insurance distribution revenue
Commissions and fees
Total commissions and fees		514	548	621
Insurance premiums
Commissions and fees
Total commissions and fees		122	288	1,224
Checking-related
Commissions and fees
Total commissions and fees		478	467	497
Loan servicing
Commissions and fees
Total commissions and fees		312	325	404
Other
Commissions and fees
Total commissions and fees		$ 327	$ 431	$ 479

[1] Certain prior-period revenue and expense lines and totals were reclassified to conform to the current period’s presentation. See Note 3 to the Consolidated Financial Statements.