SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Carrying Amounts and Classifications of Consolidated Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity
Cash and due from banks	$ 23,645	$ 23,775	$ 23,043
Trading account assets	256,117	252,790
Investments	358,607	352,290
Total loans, net of allowance	671,881	654,679
Other assets	109,273	103,926
Total assets	1,917,383	1,842,465
Significant unconsolidated VIE assets
Variable Interest Entity
Cash and due from banks	0	0
Trading account assets	8,700	8,500
Investments	5,000	4,400
Total loans, net of allowance	24,500	22,200
Other assets	500	500
Total assets	$ 38,700	$ 35,600