SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Asset Based Financing (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity
Total unconsolidated VIE assets	$ 243,175	$ 325,531
Maximum exposure to unconsolidated VIEs	47,014	43,354
Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	59,839	52,435
Maximum exposure to unconsolidated VIEs	25,939	21,943
Commercial and other real estate | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	15,370	8,784
Maximum exposure to unconsolidated VIEs	5,445	2,368
Corporate loans | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	4,725	4,051
Maximum exposure to unconsolidated VIEs	3,587	2,684
Hedge funds and equities | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	542	370
Maximum exposure to unconsolidated VIEs	58	54
Airplanes, ships and other assets | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	39,202	39,230
Maximum exposure to unconsolidated VIEs	$ 16,849	$ 16,837