VARIABLE INTEREST ENTITIES - Summary of Unconsolidated VIEs (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Equipment, net of depreciation	$ 125,247	$ 128,021
Other assets	185,863	185,946
Total assets	7,770,138	7,828,410
Total unconsolidated liabilities	6,923,179	6,921,165
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Cash	2,958	4,224
Equipment, net of depreciation	244,961	248,920
Other assets	6,751	6,301
Total assets	254,670	259,445
Total unconsolidated liabilities	6,326	7,143
Maximum loss exposure	$ 26,967	$ 32,525