Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2011	Sep. 30, 2011
Marketable securities, cost	$ 74,491,000	$ 76,275,000
Account receivable, allowance for doubtful accounts	$ 653,000	$ 582,000
Preferred stock, par value	$ 0.1	$ 0.1
Preferred stock, shares authorized	300,000	300,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.1	$ 0.1
Common stock, shares authorized	15,000,000	15,000,000
Common stock, shares issued	8,008,632	8,008,632
Common stock, shares outstanding	8,008,632	8,008,632
Class B Stock [Member]
Common stock, par value	$ 0.1	$ 0.1
Common stock, shares authorized	6,000,000	6,000,000
Common stock, shares issued	1,509,238	1,509,238
Common stock, shares outstanding	1,509,238	1,509,238