FAIR VALUE MEASUREMENTS: (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Jun. 30, 2017
Assets and liabilities measured at fair value on a nonrecurring basis
Long-term debt, fair value	$ 90,000		$ 90,000
Long-term debt	90,000		90,000		$ 120,599
Long-lived assets	300	$ 3,200	9,600	$ 7,600
Nonrecurring | Level 3
Assets and liabilities measured at fair value on a nonrecurring basis
Long-lived assets	313	$ 3,236	9,565	$ 7,622
Senior Notes | Senior Term Notes, net
Assets and liabilities measured at fair value on a nonrecurring basis
Long-term debt	$ 0		$ 0		120,599
Debt fair value					125,900
Debt, gross					123,000
Unamortized discount					1,800
Unamortized debt issuance costs					$ 600