REVENUE - Contract Receivables (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2018	Jun. 30, 2018
Contract Receivables
Royalty payments monthly due period	30 days
Royalty payments quarterly due period	45 days
Royalty receivables	$ 25,106	$ 26,356
Minimum
Contract Receivables
Royalty payments quarterly due period	30 days
Maximum
Contract Receivables
Royalty payments quarterly due period	60 days