INTEREST REVENUE AND EXPENSE (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Interest revenue
Loan interest, including fees	$ 11,981	$ 11,190	$ 23,949	$ 22,082
Deposits with banks	736	493	1,343	925
Securities borrowed or purchased under agreements to resell	1,893	1,336	3,677	2,375
Investments, including dividends	2,505	2,374	5,053	4,608
Trading account assets	2,140	1,763	3,826	3,134
Other interest	457	394	940	758
Total interest revenue	19,712	17,550	38,788	33,882
Interest expense
Deposits	3,284	2,244	6,311	4,241
Securities loaned or sold under agreements to repurchase	1,724	1,224	3,313	2,173
Trading account liabilities	320	236	647	451
Short-term borrowings	715	523	1,367	994
Long-term debt	1,719	1,658	3,441	3,186
Total interest expense	7,762	5,885	15,079	11,045
Net interest revenue	11,950	11,665	23,709	22,837
Provision for loan losses	2,089	1,795	4,033	3,598
Net interest revenue after provision for loan losses	9,861	9,870	19,676	19,239
Insurance fees and charges	$ 189	$ 319	$ 382	$ 695