OTHER FINANCIAL STATEMENT DATA - Supplementary Cash Flow Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Cash paid for:
Interest	$ 7,390	$ 4,408	$ 7,022
Taxes and penalties, net	2,150	2,096	2,397
Non-cash investing activities:
Unpaid capital expenditures	$ 2,569	$ 3,873	$ 9,209