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)	(2,238,392)				(2,238,392)
Purchase of treasury stock	(407,677)					$ (407,677)
Purchase of treasury stock, shares						(17,119)
Restricted stock awards	180,412		180,412
Dividends ($.08 per share)	(1,340,359)				(1,340,359)
Distribution of restricted stock to officers and directors	547		(895,402)			$ 895,949
Distribution of restricted stock to officers and directors, shares						56,166
Increase in deferred directors' compensation charged to expense	105,818			105,818
Balances at Dec. 31, 2016	111,492,168	$ 280,938	2,476,066	3,509,031	108,903,533	$ (3,677,400)
Balances, shares at Dec. 31, 2016		16,863,004
Balances, Treasury shares at Dec. 31, 2016						(223,661)
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)	$ 13,784,939				13,784,939
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	194,050		194,050
Dividends ($.08 per share)	(1,347,608)				(1,347,608)
Distribution of restricted stock to officers and directors	734		(735,965)			$ 736,699
Distribution of restricted stock to officers and directors, shares						44,065
Increase in deferred directors' compensation charged to expense	108,384			108,384
Balances at Dec. 31, 2017	$ 129,182,673	$ 280,938	$ 2,186,538	$ 3,568,293	$ 125,767,547	$ (2,620,643)
Balances, shares at Dec. 31, 2017		16,863,004
Balances, Treasury shares at Dec. 31, 2017	(154,044)					(154,044)