Stock-based compensation - Summary of Stock-Based Compensation Expense (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 2,177	$ 1,312	$ 3,597	$ 2,492
Cost of revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	39	21	76	48
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	889	638	1,528	1,240
Selling and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	633	319	992	534
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 616	$ 334	$ 1,001	$ 670