FAIR VALUE MEASUREMENTS: (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2018
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
Long-lived assets	1,831	$ 2,280
Nonrecurring | Level 3
Assets and liabilities measured at fair value on a nonrecurring basis
Long-lived assets	$ 1,831	$ 2,280