Statements Of Stockholders' Equity - USD ($)	Total	Class A voting Common Stock [Member]	Capital in Excess of Par Value [Member]	Deferred Directors' Compensation [Member]	Retained Earnings [Member]	Treasury Stock [Member]
Balances at Sep. 30, 2016	$ 115,191,819	$ 280,938	$ 3,191,056	$ 3,403,213	$ 112,482,284	$ (4,165,672)
Balances, shares at Sep. 30, 2016		16,863,004
Balances, Treasury shares at Sep. 30, 2016						(262,708)
Net income (loss)	1,232,041				1,232,041
Purchase of treasury stock	(407,677)					$ (407,677)
Purchase of treasury stock, shares						(17,119)
Restricted stock awards	317,633		317,633
Dividends ($.08 per share)	(1,340,656)				(1,340,656)
Distribution of restricted stock to officers and directors	584		(932,059)			$ 932,643
Distribution of restricted stock to officers and directors, shares						58,398
Distribution of deferred directors' compensation			(145,469)	(301,962)		$ 447,431
Distribution of deferred directors' compensation, shares						27,216
Increase in deferred directors' compensation charged to expense	176,368			176,368
Balances at Mar. 31, 2017	115,170,112	$ 280,938	2,431,161	3,277,619	112,373,669	$ (3,193,275)
Balances, shares at Mar. 31, 2017		16,863,004
Balances, Treasury shares at Mar. 31, 2017						(194,213)
Balances at Sep. 30, 2017	$ 116,707,539	$ 280,938	2,726,444	3,459,909	113,330,216	$ (3,089,968)
Balances, shares at Sep. 30, 2017		16,863,004
Balances, Treasury shares at Sep. 30, 2017	(184,988)					(184,988)
Net income (loss)	$ 14,855,115				14,855,115
Purchase of treasury stock	(272,100)					$ (272,100)
Purchase of treasury stock, shares						(13,404)
Issuance of treasury shares to ESOP	6,735		2,009			$ 4,726
Issuance of treasury shares to ESOP, shares						283
Restricted stock awards	347,838		347,838
Dividends ($.08 per share)	(1,347,608)				(1,347,608)
Distribution of restricted stock to officers and directors	777		(779,400)			$ 780,177
Distribution of restricted stock to officers and directors, shares						46,621
Distribution of deferred directors' compensation		$ 543	269,112	(811,219)		$ 541,564
Distribution of deferred directors' compensation, shares		32,599				31,838
Increase in deferred directors' compensation charged to expense	170,826			170,826
Balances at Mar. 31, 2018	$ 130,469,122	$ 281,481	$ 2,566,003	$ 2,819,516	$ 126,837,723	$ (2,035,601)
Balances, shares at Mar. 31, 2018		16,895,603
Balances, Treasury shares at Mar. 31, 2018	(119,650)					(119,650)