ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Fair value measured on recurring basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Contingent Consideration [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	$ 2,831	$ 1,580
Net income attributable to noncontrolling interests	0	0
Dividends paid to noncontrolling interests	0	0
Distribution	(1,207)	(1,148)
Change in fair value	297	2,399
Balance, end of period	1,921	2,831
The amount of total income (losses) for the period included in earnings attributable to the change in unrealized losses relating to assets and liabilities still held	(297)	(2,399)
Employment Agreement Award [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	25,660	32,323
Net income attributable to noncontrolling interests	0	0
Dividends paid to noncontrolling interests	0	0
Distribution	(3,591)	(1,530)
Change in fair value	4,948	(5,133)
Balance, end of period	27,017	25,660
The amount of total income (losses) for the period included in earnings attributable to the change in unrealized losses relating to assets and liabilities still held	(4,948)	5,133
Redeemable Noncontrolling Interest [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	10,232	10,780
Net income attributable to noncontrolling interests	1,132	1,163
Dividends paid to noncontrolling interests	(1,000)	(2,227)
Distribution	0	0
Change in fair value	200	516
Balance, end of period	10,564	10,232
The amount of total income (losses) for the period included in earnings attributable to the change in unrealized losses relating to assets and liabilities still held	$ 0	$ 0