Statements of Stockholders' Equity (Unaudited March 31, 2013 and March 31, 2012) (USD $)	Common Class A [Member]	Additional Paid-in Capital [Member]	Deferred Compensation, Share-based Payments [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balance at Sep. 30, 2011	$ 140,524	$ 1,924,507	$ 2,665,583	$ 79,771,563	$ (5,699,860)	$ 78,802,317
Balance (in Shares) at Sep. 30, 2011	8,431,502				(175,331)
Purchase of treasury stock					(1,158,957)	(1,158,957)
Purchase of treasury stock (in Shares)					(38,771)
Restricted stock awards		148,793				148,793
Net income				4,088,076		4,088,076
Dividends				(1,160,675)		(1,160,675)
Distribution of deferred directors' compensation		(229,296)	(406,772)		711,322	75,254
Distribution of deferred directors' compensation (in Shares)					22,132
Increase in deferred directors' compensation charged to expense			216,727			216,727
Balance at Mar. 31, 2012	140,524	1,844,004	2,475,538	82,698,964	(6,147,495)	81,011,535
Balance (in Shares) at Mar. 31, 2012	8,431,502				(191,970)
Balance at Sep. 30, 2012	140,524	2,020,229	2,676,160	84,821,395	(5,806,162)	83,852,146
Balance (in Shares) at Sep. 30, 2012	8,431,502				(181,310)
Purchase of treasury stock					(507,345)	(507,345)
Purchase of treasury stock (in Shares)					(18,056)
Restricted stock awards		399,907				399,907
Net income				3,170,785		3,170,785
Dividends				(1,164,178)		(1,164,178)
Distribution of deferred directors' compensation		(82,547)	(297,154)		394,687	14,986
Distribution of deferred directors' compensation (in Shares)					12,361
Increase in deferred directors' compensation charged to expense			201,211			201,211
Balance at Mar. 31, 2013	$ 140,524	$ 2,337,589	$ 2,580,217	$ 86,828,002	$ (5,918,820)	$ 85,967,512
Balance (in Shares) at Mar. 31, 2013	8,431,502				(187,005)