ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Fair Value Measurements (Details) - USD ($)
$ in Thousands
Mar. 31, 2020
Dec. 31, 2019
Liabilities subject to fair value measurement:    
Contingent consideration $ 1,500 $ 1,921
Employment agreement award 27,598 27,017
Total 29,098 28,938
Mezzanine equity subject to fair value measurement:    
Redeemable noncontrolling interests 10,292 10,564
Fair Value, Inputs, Level 3 [Member]    
Liabilities subject to fair value measurement:    
Contingent consideration 1,500 1,921
Employment agreement award 27,598 27,017
Total 29,098 28,938
Mezzanine equity subject to fair value measurement:    
Redeemable noncontrolling interests $ 10,292 $ 10,564