SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Carrying Amounts and Classifications of Consolidated Assets (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Variable Interest Entity
Cash	$ 22,604	$ 23,043	$ 23,419	$ 20,900
Trading account assets	258,907	243,925
Investments	354,674	353,304
Total loans, net of allowance	640,817	612,309
Other	130,312	128,008
Total assets	1,889,133	1,792,077
Significant unconsolidated VIE assets
Variable Interest Entity
Cash	100	100
Trading account assets	8,600	8,000
Investments	4,700	4,400
Total loans, net of allowance	18,200	18,800
Other	500	1,500
Total assets	$ 32,100	$ 32,800