Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended		9 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
Net revenue	$ 10,547,000	$ 18,690,000	$ 35,107,000	$ 41,375,000
Costs and expenses:
Production costs	8,266,000	13,720,000	27,604,000	31,662,000
Product engineering and development	352,000	420,000	1,083,000	1,322,000
Selling, general and administrative	1,557,000	1,867,000	4,810,000	5,810,000
Total operating expenses	10,175,000	16,007,000	33,497,000	38,794,000
Operating income	372,000	2,683,000	1,610,000	2,581,000
Other income (expense), net:
Interest and dividend income, net of fees	168,000	516,000	1,598,000	1,759,000
Net realized and unrealized gains on marketable securities	1,658,000	145,000	2,881,000	888,000
Other	442,000	18,000	434,000	33,000
Other income (expense), net	2,268,000	679,000	4,913,000	2,680,000
Income before income tax expense	2,640,000	3,362,000	6,523,000	5,261,000
Income tax expense	977,000	873,000	2,513,000	771,000
Net Income	$ 1,663,000	$ 2,489,000	$ 4,010,000	$ 4,490,000
Basic Income per Common Share:
Net income per share	$ 0.17	$ 0.26	$ 0.42	$ 0.47
Diluted Income per Common Share:
Net income per share	$ 0.17	$ 0.26	$ 0.42	$ 0.47