Balance sheet information - Intangibles and Other Accrued Expenses (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
Balance Sheet Related Disclosures [Abstract]
Goodwill	$ 28,700		$ 28,700		$ 28,700
Acquired developed technology	13,875		13,875		13,875
Less accumulated amortization	(12,058)		(12,058)		(11,491)
Intangible assets, net	1,817		1,817		2,384
Amortization of intangible assets	283	$ 283	567	$ 566
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2019	436		436
2020	872		872
2021	509		509
Accrued Liabilities, Current [Abstract]
Accrued compensation and benefits	6,923		6,923		12,024
Accrued royalties	12,218		12,218		16,298
Customer overpayments and related reserves	3,409		3,409		5,356
Other accrued expenses	6,817		6,817		5,125
Total accrued expenses	$ 29,367		$ 29,367		$ 38,803	[1]

[1] See Note 1 for a summary of adjustments.