Income taxes - Additional Information (Details) (USD $)	12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2012
Operating Loss Carryforwards [Line Items]
Provision (benefit) for income taxes	$ (4,015,000)	$ 1,093,000	$ 13,559,000
Effective tax rate (in percent)	12.00%	16.00%	30.00%
Change in valuation allowance - federal	6,959,000	0	0
Increase (decrease) in valuation allowance	10,100,000	699,000	264,000
Earnings of foreign subsidiaries that are permanently reinvested and no U.S. income taxes have been provided	3,600,000
Unrecognized deferred tax liability related to undistributed foreign earnings	480,000
Unrecognized tax benefits that if recognized would affect the annual effective tax rate	5,500,000	4,800,000	3,600,000
Amount of possible decrease in unrecognized tax benefits within the next 12 months	1,600,000
Unrecognized tax benefits - interest and penalties expense	278,000	159,000	101,000
Unrecognized tax benefits - interest and penalties accrued	603,000	314,000
Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	2,300,000
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	26,500,000
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	9,000,000
Research Tax Credit Carryforward | Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Research and development tax credit carryforwards	383,000
Research Tax Credit Carryforward | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Research and development tax credit carryforwards	$ 3,400,000