Statements Of Stockholders' Equity (USD $)	Class A voting Common Stock [Member]	Capital in Excess of Par Value [Member]	Deferred Directors' Compensation [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balances at Sep. 30, 2013	$ 280,938	$ 2,447,424	$ 2,756,526	$ 96,454,449	$ (6,283,851)	$ 95,655,486
Balances, Treasury shares at Sep. 30, 2013					(400,496)
Balances, shares at Sep. 30, 2013	16,863,004
Purchase of treasury stock					(122,044)	(122,044)
Purchase of treasury stock, shares					(7,444)
Restricted stock awards		127,976				127,976
Net income				4,926,318		4,926,318
Dividends				(1,328,272)		(1,328,272)
Distribution of restricted stock to officers and directors		(259,511)			275,662	16,151
Distribution of restricted stock to officers and directors, shares					18,280
Increase in deferred directors' compensation charged to expense			114,069			114,069
Balances at Dec. 31, 2013	280,938	2,315,889	2,870,595	100,052,495	(6,130,233)	99,389,684
Balances, Treasury shares at Dec. 31, 2013					(389,660)
Balances, shares at Dec. 31, 2013	16,863,004
Balances at Sep. 30, 2014	280,938	2,861,343	3,110,351	118,794,188	(5,858,167)	119,188,653
Balances, Treasury shares at Sep. 30, 2014					(372,364)	(372,364)
Balances, shares at Sep. 30, 2014	16,863,004
Purchase of treasury stock					(120,611)	(120,611)
Purchase of treasury stock, shares					(7,177)
Restricted stock awards		165,111				165,111
Net income				10,233,761		10,233,761
Dividends				(1,333,023)		(1,333,023)
Distribution of restricted stock to officers and directors		(436,303)			377,502	(58,801)
Distribution of restricted stock to officers and directors, shares					23,983
Increase in deferred directors' compensation charged to expense			101,589			101,589
Balances at Dec. 31, 2014	$ 280,938	$ 2,590,151	$ 3,211,940	$ 127,694,926	$ (5,601,276)	$ 128,176,679
Balances, Treasury shares at Dec. 31, 2014					(355,558)	(355,558)
Balances, shares at Dec. 31, 2014	16,863,004