Consolidated Statements of Shareholders' Equity - USD ($)	Total	Capital in Excess of Par Value [Member]	Retained Earnings [Member]	Common Stock [Member]	Class B Stock [Member]
Beginning balance at Sep. 30, 2013	$ 110,428,000	$ 10,292,000	$ 99,184,000	$ 801,000	$ 151,000
Beginning balance, shares at Sep. 30, 2013				8,008,632	1,509,238
Net income (loss)	3,473,000		3,473,000
Stock-based compensation	263,000	263,000
Stock options exercised	11,000	11,000
Stock options exercised, shares				1,500
Ending balance at Sep. 30, 2014	114,175,000	10,566,000	102,657,000	$ 801,000	$ 151,000
Ending balance, shares at Sep. 30, 2014				8,010,132	1,509,238
Net income (loss)	(1,819,000)		(1,819,000)
Stock-based compensation	253,000	253,000
Stock options exercised	136,000	134,000		$ 2,000
Stock options exercised, shares				18,750
Ending balance at Sep. 30, 2015	$ 112,745,000	$ 10,953,000	$ 100,838,000	$ 803,000	$ 151,000
Ending balance, shares at Sep. 30, 2015				8,028,882	1,509,238