SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Asset Based Financing (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Variable Interest Entity
Total unconsolidated VIE assets	$ 300,145	$ 291,992
Maximum exposure to unconsolidated VIEs	57,311	55,534
Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	105,153	98,805
Maximum exposure to unconsolidated VIEs	34,168	32,112
Commercial and other real estate | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	25,189	23,918
Maximum exposure to unconsolidated VIEs	6,530	6,928
Corporate loans | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	7,438	6,973
Maximum exposure to unconsolidated VIEs	7,277	5,744
Hedge funds and equities | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	444	388
Maximum exposure to unconsolidated VIEs	53	53
Airplanes, ships and other assets | Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	72,082	67,526
Maximum exposure to unconsolidated VIEs	$ 20,308	$ 19,387