INCOME TAXES - Unrecognized Tax Benefits Roll Forward (Details) - USD ($)
$ in Thousands
12 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]      
Unrecognized benefit—beginning of year $ 29,144 $ 27,438 $ 22,851
Gross increases—current year tax positions 3,852 4,762 5,184
Gross decreases—prior year tax positions due to statute lapse (2,146) (3,056) (597)
Unrecognized benefit—end of year $ 30,850 $ 29,144 $ 27,438