Summary of business and significant accounting policies - Research and Software Development Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Finite-Lived Intangible Assets [Line Items]
Deferred software development costs during period	$ 3,200	$ 648	$ 802
Deferred capitalized software development costs	3,100	33
Cost of revenue
Finite-Lived Intangible Assets [Line Items]
Amortization expense related to capitalized software costs	0	0	100
Development costs expensed	$ 120	$ 660	$ 1,200
Computer software | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful lives/amortization period	18 months
Computer software | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful lives/amortization period	24 months