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, 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)
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)
Balances at Sep. 30, 2018	$ 128,765,205	$ 281,502	2,824,691	2,950,405	125,266,945	$ (2,558,338)
Balances, shares at Sep. 30, 2018		16,896,881
Balances, Treasury shares at Sep. 30, 2018	(145,467)					(145,467)
Net income (loss)	$ 12,735,940				12,735,940
Purchase of treasury stock	(1,140,559)					$ (1,140,559)
Purchase of treasury stock, shares						(74,457)
Restricted stock awards	159,469		159,469
Dividends ($.08 per share)	(1,347,789)				(1,347,789)
Distribution of restricted stock to officers and directors	160	$ 7	(159,869)			$ 160,022
Distribution of restricted stock to officers and directors, shares		425				9,194
Distribution of deferred directors' compensation			(8)	8
Increase in deferred directors' compensation charged to expense	80,287			80,287
Balances at Dec. 31, 2018	$ 139,252,713	$ 281,509	$ 2,824,283	$ 3,030,700	$ 136,655,096	$ (3,538,875)
Balances, shares at Dec. 31, 2018		16,897,306
Balances, Treasury shares at Dec. 31, 2018	(210,730)					(210,730)