Stock-based compensation - Stock Options and RSUs (Details) - $ / shares	3 Months Ended
	Mar. 31, 2016	Jun. 30, 2015
Number of Shares
Exercised/Converted		(895,655)
Employee Stock Options
Number of Shares
Beginning Balance	5,007,797
Granted	12,300
Exercised/Converted	(349,954)
Cancelled/Forfeited	(30,108)
Ending Balance	4,640,035
Weighted Average Exercise Price
Beginning Balance	$ 4.34
Granted	10.40
Exercised/Converted	3.52
Cancelled/Forfeited	6.05
Ending Balance	$ 4.41
Restricted stock units
Number of Units
Beginning Balance	1,213,686
Granted	16,900
Exercised/Converted	(8,001)
Cancelled/Forfeited	(7,618)
Ending Balance	1,214,967
Weighted Average Exercise Price
Beginning Balance	$ 7.46
Granted	9.19
Exercised/Converted	7.65
Cancelled/Forfeited	7.36
Ending Balance	$ 7.49