SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Carrying Amounts and Classifications of Consolidated Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity
Cash and due from banks	$ 23,967	$ 23,645	$ 23,775
Trading account assets	276,140	256,117
Investments	368,563	358,607
Total loans, net of allowance	686,700	671,881
Other assets	107,709	109,273
Total assets	1,951,158	1,917,383
Significant unconsolidated VIE assets
Variable Interest Entity
Cash and due from banks	0	0
Trading account assets	2,600	3,000
Investments	9,900	10,700
Total loans, net of allowance	26,700	24,500
Other assets	500	500
Total assets	$ 39,700	$ 38,700