FAIR VALUE MEASUREMENTS: (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2018
Assets and liabilities measured at fair value on a nonrecurring basis
Long-term debt, fair value	$ 90,000		$ 90,000		$ 90,000
Long-term debt	90,000		90,000		90,000
Long-term lease liability	17,646		17,646		$ 0
Long-lived assets			2,303	$ 16,715
Level 2
Assets and liabilities measured at fair value on a nonrecurring basis
Long-term lease liability	17,600		17,600
Nonrecurring | Level 3
Assets and liabilities measured at fair value on a nonrecurring basis
Long-lived assets	$ 472	$ 14,435	$ 2,303	$ 16,715