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, 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)
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	(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)
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)
Net income (loss)	15,408,842
Balances at Jun. 30, 2019	136,500,196	$ 281,509	2,937,874	2,481,109	138,662,782	$ (7,863,078)
Balances, shares at Jun. 30, 2019		16,897,306
Balances, Treasury shares at Jun. 30, 2019						(508,582)
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)
Net income (loss)	(1,931,334)				(1,931,334)
Purchase of treasury stock	(2,827,126)					$ (2,827,126)
Purchase of treasury stock, shares						(175,175)
Restricted stock awards	286,852		286,852
Dividends	(381)				(381)
Distribution of restricted stock to officers and directors	75		(73,069)			$ 73,144
Distribution of restricted stock to officers and directors, shares						4,441
Distribution of deferred Directors' compensation	(3)		(207,842)	(667,124)		$ 874,963
Distribution of deferred directors' compensation, shares						52,399
Increase in deferred directors' compensation charged to expense	51,993			51,993
Balances at Mar. 31, 2019	134,832,789	$ 281,509	2,830,224	2,415,569	134,723,381	$ (5,417,894)
Balances, shares at Mar. 31, 2019		16,897,306
Balances, Treasury shares at Mar. 31, 2019						(329,065)
Net income (loss)	4,604,236				4,604,236
Purchase of treasury stock	(2,497,501)					$ (2,497,501)
Purchase of treasury stock, shares						(182,901)
Restricted stock awards	159,911		159,911
Dividends	(664,835)				(664,835)
Distribution of restricted stock to officers and directors	56		(52,261)			$ 52,317
Distribution of restricted stock to officers and directors, shares						3,384
Increase in deferred directors' compensation charged to expense	65,540			65,540
Balances at Jun. 30, 2019	136,500,196	$ 281,509	2,937,874	2,481,109	138,662,782	$ (7,863,078)
Balances, shares at Jun. 30, 2019		16,897,306
Balances, Treasury shares at Jun. 30, 2019						(508,582)
Balances at Sep. 30, 2019	$ 79,309,533	$ 281,509	2,967,984	2,555,781	81,848,301	$ (8,344,042)
Balances, shares at Sep. 30, 2019		16,897,306
Balances, Treasury shares at Sep. 30, 2019	(558,051)					(558,051)
Net income (loss)	$ 1,892,114				1,892,114
Purchase of treasury stock	(7,635)					$ (7,635)
Purchase of treasury stock, shares						(632)
Restricted stock awards	148,515		148,515
Dividends	(1,319,899)				(1,319,899)
Distribution of restricted stock to officers and directors	93		(82,821)			$ 82,914
Distribution of restricted stock to officers and directors, shares						5,546
Increase in deferred directors' compensation charged to expense	86,212			86,212
Balances at Dec. 31, 2019	80,108,933	$ 281,509	3,033,678	2,641,993	82,420,516	$ (8,268,763)
Balances, shares at Dec. 31, 2019		16,897,306
Balances, Treasury shares at Dec. 31, 2019						(553,137)
Balances at Sep. 30, 2019	$ 79,309,533	$ 281,509	2,967,984	2,555,781	81,848,301	$ (8,344,042)
Balances, shares at Sep. 30, 2019		16,897,306
Balances, Treasury shares at Sep. 30, 2019	(558,051)					(558,051)
Net income (loss)	$ (22,117,915)
Balances at Jun. 30, 2020	$ 56,502,044	$ 281,509	3,375,400	1,829,786	58,244,355	$ (7,229,006)
Balances, shares at Jun. 30, 2020		16,897,306
Balances, Treasury shares at Jun. 30, 2020	(483,588)					(483,588)
Balances at Dec. 31, 2019	$ 80,108,933	$ 281,509	3,033,678	2,641,993	82,420,516	$ (8,268,763)
Balances, shares at Dec. 31, 2019		16,897,306
Balances, Treasury shares at Dec. 31, 2019						(553,137)
Net income (loss)	(20,454,814)				(20,454,814)
Restricted stock awards	343,101		343,101
Distribution of deferred Directors' compensation	(1)		(112,396)	(603,485)		$ 715,880
Distribution of deferred directors' compensation, shares						47,885
Increase in deferred directors' compensation charged to expense	53,918			53,918
Balances at Mar. 31, 2020	60,051,137	$ 281,509	3,264,383	2,092,426	61,965,702	$ (7,552,883)
Balances, shares at Mar. 31, 2020		16,897,306
Balances, Treasury shares at Mar. 31, 2020						(505,252)
Net income (loss)	(3,555,215)				(3,555,215)
Restricted stock awards	128,196		128,196
Dividends	(166,132)				(166,132)
Distribution of deferred Directors' compensation			(17,179)	(306,698)		$ 323,877
Distribution of deferred directors' compensation, shares						21,664
Increase in deferred directors' compensation charged to expense	44,058			44,058
Balances at Jun. 30, 2020	$ 56,502,044	$ 281,509	$ 3,375,400	$ 1,829,786	$ 58,244,355	$ (7,229,006)
Balances, shares at Jun. 30, 2020		16,897,306
Balances, Treasury shares at Jun. 30, 2020	(483,588)					(483,588)