v3.19.1
SHARE-BASED COMPENSATION - RSUs with Market Conditions (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Dec. 31, 2018
Dec. 31, 2018
Share-based Compensation Restricted Stock Units With Market Conditions [Line Items]        
RSUs issued 1,489      
Reconciliation Of RSUs With Market Conditions [Abstract]        
RSUs beginning 3,685      
Number of RSUs granted 1,489      
Number of RSUs forfeited (83)      
Number of RSUs vested (636)      
RSUs ending 4,455   3,685 3,685
Net RSUs increase (decrease) to APIC $ 3,573 $ 3,913 $ 11,236  
Restricted Stock Units With Market Conditions [Member]        
Share-based Compensation Restricted Stock Units With Market Conditions [Line Items]        
RSUs issued 0     0
Reconciliation Of RSUs With Market Conditions [Abstract]        
RSUs beginning 226 650   650
Number of RSUs granted 0     0
Number of RSUs forfeited (6)     (110)
Number of RSUs vested 0     (314)
RSUs ending 220   226 226
Fair value of each RSU issued with market conditions $ 0     $ 0