Balance sheet information - Other Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017
Balance Sheet Related Disclosures [Abstract]
Accrued compensation and benefits	$ 12,024	$ 10,554
Accrued royalties	16,298	28,179
Accrued legal settlement and contingencies	50	0
Customer overpayments and related reserves	5,356	5,940
Other accrued expenses	5,075	6,855
Accrued expenses	$ 38,803	$ 51,528