Income Taxes - Deferred Tax Assets and Liabilities - (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017
Deferred tax assets arising from:
Accrued liabilities and reserves	$ 157	$ 492
Deferred revenue	32	95
Bad debt reserves	20	52
Tangible property	73	127
Inventory reserves	513	756
Intangible assets	1,655	2,381
Other	6	43
Share-based compensation	179	161
Foreign tax credit carryforward	451	288
Research and development tax credits	238	311
Alternative minimum tax credits		318
Tax effects of net operating loss carryforwards	5,273	3,855
Less valuation allowances	(6,414)	(4,933)
Deferred tax assets	2,183	3,946
Deferred tax liabilities arising from:
Property and equipment	(2,144)	(3,533)
Prepaid expenses	(28)	(126)
Unrealized foreign currency gain	(11)	(27)
Deferred tax liabilities	(2,183)	(3,686)
Net deferred tax asset		260
Other current assets
Income tax receivable
Income tax receivable	$ 500	$ 500