Condensed Consolidated Statements of Income (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Net revenue	$ 19,863,000	$ 10,940,000	$ 55,199,000	$ 30,981,000
Costs and expenses:
Production costs	14,712,000	8,541,000	41,325,000	24,603,000
Product engineering and development	379,000	351,000	1,140,000	1,038,000
Selling, general and administrative	1,979,000	1,703,000	5,954,000	5,130,000
Total costs and expenses	17,070,000	10,595,000	48,419,000	30,771,000
Operating income	2,793,000	345,000	6,780,000	210,000
Other income (expense), net:
Interest and dividend income, net of fees	99,000	152,000	688,000	672,000
Net realized and unrealized gains (losses) on marketable securities	464,000	(77,000)	567,000	(309,000)
Other		2,000	2,000	2,000
Other income (expense), net	563,000	77,000	1,257,000	365,000
Income before income tax expense	3,356,000	422,000	8,037,000	575,000
Income tax expense	1,242,000	156,000	2,718,000	221,000
Net income	$ 2,114,000	$ 266,000	$ 5,319,000	$ 354,000
Basic Income per Common Share:
Net income per share	$ 0.22	$ 0.03	$ 0.56	$ 0.04
Diluted Income per Common Share:
Net income per share	$ 0.22	$ 0.03	$ 0.55	$ 0.04