Income taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jun. 30, 2018
Deferred tax assets:
Federal, state and foreign net operating losses	$ 57,809	$ 55,540
Federal and state tax credits	14,104	12,195
Stock-based compensation	2,885	3,481
Accrued expenses and reserves	13,659	9,395
Capitalized expense	34	60
Unrealized losses	481	609
Property and equipment	43	0
Acquired intangible assets	768	652
Total deferred tax assets	89,783	81,932
Deferred tax liabilities:
Property and equipment	(79)	(29)
Capitalized software	(17,848)	(13,222)
Deferred revenue	(22,486)	0
Unrealized gains	(236)	(451)
Total deferred tax liabilities:	(40,649)	(13,702)
Deferred tax assets, net of liabilities:	49,134	68,230
Valuation allowance — worldwide	(48,370)	(67,702)
Net deferred tax assets	$ 764	$ 528