COMMITMENTS AND CONTINGENCIES - Deferred FI Implementation Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Deferred Financial Institution Costs [Roll Forward]
Beginning balance	$ 7,375	$ 14,067	$ 8,383	$ 15,877
Recoveries through FI Share	0	(1,155)	0	(2,312)
Amortization	991	731	1,999	1,384
Ending balance	$ 6,384	$ 12,181	$ 6,384	$ 12,181