Income taxes (Details) (USD $)	9 Months Ended		6 Months Ended	0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Jan. 01, 2015	Jun. 30, 2014	Jan. 31, 2015
Operating Loss Carryforwards [Line Items]
Effective tax rate	40.00%	35.00%
Expected tax refund resulting from operating loss carryforwards	$ (2,354,000)	$ 3,474,000
Unrecognized tax benefit	4,200,000				6,900,000
Unrecognized tax benefits that would affect effective tax rate	2,300,000				5,500,000
Interest and penalties related to unrecognized tax positions accrued	525,000				603,000
Deferred tax assets valuation allowance					13,000,000
Tax Year 2014
Operating Loss Carryforwards [Line Items]
Income tax true up adjustments related to 2014 tax return	1,500,000
January 2014 - June 2014
Operating Loss Carryforwards [Line Items]
Tax benefit recognized related to research and development credit			400,000
Domestic Tax Authority | Internal Revenue Service (IRS) | Tax Year 2014
Operating Loss Carryforwards [Line Items]
Income tax refund received				8,000,000
Income taxes receivable						8,600,000
State and Local Jurisdiction | California Franchise Tax Board | Tax Year 2009 and 2010
Operating Loss Carryforwards [Line Items]
State income taxes refund from amended returns	3,000,000
Income tax refund received				3,000,000
Expected tax refund resulting from operating loss carryforwards	$ 3,000,000