Cash, cash equivalents and short-term investments - Schedule of Cash, Cash Equivalents and Short-Term Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Debt Securities, Available-for-sale [Line Items]
Cash	$ 20,323	$ 25,987
Cash equivalents	195	1,288
Cash and cash equivalents	20,518	27,275	$ 17,117
Debt securities
Amortized Cost	88,745	70,493
Unrealized Gains		404
Unrealized Losses		(43)
Estimated Fair Value	90,315	70,854
Marketable equity securities
Amortized Cost		250
Unrealized Gains		1,099
Unrealized Losses		0
Estimated Fair Value	0	1,349
Short-term investments
Amortized Cost	88,745	70,743
Unrealized Gains	1,570	1,503
Unrealized Losses	0	(43)
Short-term investments	90,315	72,203
Cash, cash equivalents and short-term investments
Amortized Cost	109,263	98,018
Unrealized Gains	1,570	1,503
Unrealized Losses	0	(43)
Estimated Fair Value	110,833	99,478
U.S. treasury securities
Debt securities
Amortized Cost	3,712	3,570
Unrealized Gains	41	6
Unrealized Losses	0	(4)
Estimated Fair Value	3,753	3,572
U.S. agency securities
Debt securities
Amortized Cost	5,004	3,002
Unrealized Gains	54	9
Unrealized Losses	0	(2)
Estimated Fair Value	5,058	3,009
Asset-backed securities
Debt securities
Amortized Cost	20,392	12,319
Unrealized Gains	434	104
Unrealized Losses	0	(10)
Estimated Fair Value	20,826	12,413
Municipal securities
Debt securities
Amortized Cost	9,464	4,124
Unrealized Gains	78	16
Unrealized Losses	0	0
Estimated Fair Value	9,542	4,140
Commercial paper
Debt securities
Amortized Cost		1,986
Unrealized Gains		0
Unrealized Losses		0
Estimated Fair Value	0	1,986
Corporate bonds
Debt securities
Amortized Cost	50,173	45,492
Unrealized Gains	963	269
Unrealized Losses	0	(27)
Estimated Fair Value	51,136	45,734
Money market mutual funds
Debt Securities, Available-for-sale [Line Items]
Cash equivalents	$ 195	790
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Cash equivalents		$ 498