Summary of business and significant accounting policies - Research and Software Development Costs (Details) - USD ($)	12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Finite-Lived Intangible Assets [Line Items]
Capitalized software development costs during period	$ 0	$ 0	$ 948,000
Write-off of capitalized software development costs due to impairment	0	0	112,000
Deferred software development costs during period	802,000	943,000	1,300,000
Deferred capitalized software development costs	44,000	500,000
Other assets
Finite-Lived Intangible Assets [Line Items]
Unamortized capitalized software development costs	0	97,000
Cost of revenue
Finite-Lived Intangible Assets [Line Items]
Amortization expense related to capitalized software costs	97,000	1,000,000	2,100,000
Development costs expensed	$ 1,200,000	$ 922,000	$ 4,900,000
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