INTEREST REVENUE AND EXPENSE (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest revenue
Loan interest, including fees		$ 45,682	$ 41,736	$ 40,125
Deposits with banks		2,203	1,635	971
Federal funds sold and securities borrowed or purchased under agreements to resell		5,492	3,249	2,543
Investments, including dividends		9,494	8,295	7,582
Trading account assets		6,284	5,501	5,738
Other interest		1,673	1,163	1,029
Total interest revenue	[1]	70,828	61,579	57,988
Interest expense
Deposits		9,616	6,587	5,300
Federal funds purchased and securities loaned or sold under agreements to repurchase		4,889	2,661	1,912
Trading account liabilities		1,001	638	410
Short-term borrowings		2,209	1,059	477
Long-term debt		6,551	5,573	4,413
Total interest expense	[1]	24,266	16,518	12,512
Net interest revenue	[1]	46,562	45,061	45,476
Provision for loan losses		7,354	7,503	6,749
Net interest revenue after provision for loan losses		39,208	37,558	38,727
Insurance fees and charges		$ 1,182	$ 1,249	$ 1,145

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