Quarterly financial data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2019		Jun. 30, 2018	[1]	Jun. 30, 2017	[1]
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 58,452	$ 53,069	$ 57,176	$ 52,199	$ 55,987	$ 46,382	$ 61,399	$ 54,695	$ 220,896		$ 218,463		$ 209,715
Gross profit	26,357	23,442	24,985	21,437	24,164	21,715	23,523	20,990	96,221		90,392		89,279
Net loss	$ (12,856)	$ (7,481)	$ (4,581)	$ (7,570)	$ (7,465)	$ (14,457)	$ (8,394)	$ (10,518)	$ (32,488)	[2]	$ (40,834)	[2]	$ (29,536)	[2]
Net loss per share:
Basic and diluted (in dollars per share)	$ (0.28)	$ (0.16)	$ (0.10)	$ (0.17)	$ (0.17)	$ (0.32)	$ (0.19)	$ (0.24)	$ (0.71)		$ (0.92)		$ (0.68)

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

[2] See Note 1 for a summary of adjustments. The cumulative effect adjustment to Accumulated Deficit and Total Stockholders' Equity related to the adoption of ASU No. 2014-09 (Topic 606) as of June 30, 2016 was $11.8 million.