Stock-based compensation - Summary of Stock Option Activity (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
	Dec. 31, 2012	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding as of June 30, 2012		7,707
Granted		1,027
Exercised		(753)
Canceled		(576)
Options outstanding as of December 31, 2012	7,405	7,405
Options vested and expected to vest	7,053	7,053
Options exercisable	3,773	3,773
Weighted Average Exercise Price
Options outstanding	$ 5.89	$ 5.89
Options vested and expected to vest	$ 5.82	$ 5.82
Options exercisable	$ 4.64	$ 4.64
Weighted Average Remaining Contractual Life
Options outstanding	6 years 11 months 5 days
Options vested and expected to vest	6 years 10 months 13 days
Options exercisable	5 years 6 months 11 days
Aggregate Intrinsic Value
Options outstanding	$ 18,886	$ 18,886
Options vested and expected to vest	18,512	18,512
Options exercisable	$ 14,364	$ 14,364