Condensed Consolidated Statements of Operations (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Net revenue	$ 10,940,000	$ 10,547,000	$ 30,981,000	$ 35,107,000
Costs and expenses:
Production costs	8,541,000	8,266,000	24,603,000	27,604,000
Product engineering and development	351,000	352,000	1,038,000	1,083,000
Selling, general and administrative	1,703,000	1,557,000	5,130,000	4,810,000
Total operating expenses	10,595,000	10,175,000	30,771,000	33,497,000
Operating income	345,000	372,000	210,000	1,610,000
Other income (expense), net:
Interest and dividend income, net of fees	152,000	168,000	672,000	1,598,000
Net realized and unrealized gains (losses) on marketable securities	(77,000)	1,658,000	(309,000)	2,881,000
Other	2,000	442,000	2,000	434,000
Other income (expense), net	77,000	2,268,000	365,000	4,913,000
Income before income tax expense	422,000	2,640,000	575,000	6,523,000
Income tax expense	156,000	977,000	221,000	2,513,000
Net Income	$ 266,000	$ 1,663,000	$ 354,000	$ 4,010,000
Basic Income per Common Share:
Net income per share	$ 0.03	$ 0.17	$ 0.04	$ 0.42
Diluted Income per Common Share:
Net income per share	$ 0.03	$ 0.17	$ 0.04	$ 0.42