Income Taxes - Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Income Tax Benefit Expenses [Line Items]
Beginning balance of gross unrecognized tax benefits, Tax	$ 148	$ 102
Increases to unrecognized tax benefits resulting from the generation of additional R&D credits, Tax	35	46
Ending balance of gross unrecognized tax benefits, Tax	183	148
Beginning balance of gross unrecognized tax benefits, Interest	0	0
Increases to unrecognized tax benefits resulting from the generation of additional R&D credits, Interest	0	0
Ending balance of gross unrecognized tax benefits, Interest	0	0
Beginning balance of gross unrecognized tax benefits	148	102
Increases to unrecognized tax benefits resulting from the generation of additional R&D credits	35	46
Ending balance of gross unrecognized tax benefits	$ 183	$ 148