CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Net sales	$ 4,599	$ 5,231	$ 9,728	$ 9,023
Cost of sales	3,288	3,806	6,995	6,694
Gross profit	1,311	1,425	2,733	2,329
Operating expenses:
Selling expenses	159	223	421	394
General and administrative expenses	605	452	1,169	986
Research and development costs	278	264	581	528
Total operating expenses	1,042	939	2,171	1,908
Operating income	269	486	562	421
Interest expense	(4)	(20)	(7)	(26)
Interest income	11	1	12
Gain from disposal of equipment		14	3	14
Income from continuing operations before income taxes	276	481	570	409
Income tax (expense) benefit	2,859		2,852	(1)
Income from continuing operations	3,135	481	3,422	408
Income (loss) from discontinued operations, net of income taxes	59	(90)	58	(143)
Net income	3,194	391	3,480	265
Other comprehensive income (loss), net of tax:
Unrealized loss from marketable equity investments	(6)		(6)
Comprehensive income	$ 3,188	$ 391	$ 3,474	$ 265
Basic net income per share:
Income from continuing operations (in dollars per share)	$ 0.77	$ 0.11	$ 0.84	$ 0.1
Income (loss) from discontinued operations (in dollars per share)	0.02	(0.02)	0.01	(0.04)
Net income (in dollars per share)	0.79	0.09	0.85	0.06
Diluted net income per share:
Income from continuing operations (in dollars per share)	0.77	0.11	0.84	0.1
Income (loss) from discontinued operations (in dollars per share)	0.01	(0.02)	0.01	(0.04)
Net income (in dollars per share)	$ 0.78	$ 0.09	$ 0.85	$ 0.06
Weighted average common shares outstanding:
Basic (in shares)	4,057	4,143	4,060	4,142
Diluted (in shares)	4,092	4,165	4,098	4,161
Common shares outstanding (in shares)	4,040	4,149	4,040	4,149