v3.10.0.1
SHARE-BASED COMPENSATION - RSUs with Market Conditions (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Share-based Compensation Restricted Stock Units With Market Conditions [Line Items]        
RSUs issued   1,284,050    
Reconciliation Of RSUs With Market Conditions [Abstract]        
RSUs beginning   4,285,290    
Number of RSUs granted   1,284,050    
Number of RSUs forfeited   (339,317)    
Number of RSUs vested   (1,492,544)    
RSUs ending 4,285,290 3,737,479   4,285,290
Net RSUs increase (decrease) to APIC $ 4,938 $ 11,421 $ 4,629  
Restricted Stock Units With Market Conditions [Member]        
Share-based Compensation Restricted Stock Units With Market Conditions [Line Items]        
RSUs issued   0   70,000
Reconciliation Of RSUs With Market Conditions [Abstract]        
RSUs beginning   650,000 630,000 630,000
Number of RSUs granted   0   70,000
Number of RSUs forfeited   (110,000)   0
Number of RSUs vested   (314,000)   (50,000)
RSUs ending 650,000 226,000   650,000
Fair value of each RSU issued with market conditions   $ 0   $ 9.81