STOCK BASED COMPENSATION - Option activity for company's stock incentive plans (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Number of Shares
Beginning balance (in shares)	2,125,307	2,301,144	2,657,142
Exercised (in shares)	(502,350)	(171,263)	(299,034)
Forfeitures and cancellations (in shares)	(1,356)	(4,574)	(56,964)
Ending balance (in shares)	1,621,601	2,125,307	2,301,144	2,657,142
Number of shares, vested and expected to vest, ending balance (in shares)	1,621,601
Number of shares, vested and exercisable, ending balance (in shares)	1,621,601
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 2.03	$ 2.38	$ 2.96
Exercised (in dollars per share)	2.86	6.46	5.64
Forfeitures and cancellations (in dollars per share)	11.72	13.82	12.14
Ending balance (in dollars per share)	1.76	$ 2.03	$ 2.38	$ 2.96
Options, weighted average exercise price, vested and expected to vest (in dollars per share)	1.76
Options, weighted average exercise price, vested and exercisable (in dollars per share)	$ 1.76
Options outstanding, weighted average remaining contractual term	1 year 6 months 18 days	2 years 7 months 24 days	3 years 9 months 26 days	5 years 1 month 10 days
Options, remaining contractual term, vested and expected to vest	1 year 6 months 18 days
Options, weighted average remaining contractual term, vested and exercisable	1 year 6 months 18 days
Options outstanding, intrinsic value	$ 81,413	$ 77,850	$ 67,969	$ 112,215
Options, aggregate intrinsic value, vested and expected to vest	81,413
Options, aggregate intrinsic value, vested and exercisable	$ 81,413