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)	2,492,799				2,492,799
Purchase of treasury stock	(407,677)					$ (407,677)
Purchase of treasury stock, shares						(17,119)
Issuance of treasury shares to ESOP	(18)		(2)			$ (16)
Issuance of treasury shares to ESOP, shares						(1)
Restricted stock awards	454,854		454,854
Dividends ($.12 per share)	(2,012,329)				(2,012,329)
Distribution of restricted stock to officers and directors	622		(968,617)			$ 969,239
Distribution of restricted stock to officers and directors, shares						60,624
Distribution of deferred directors' compensation	(1)		(145,469)	(301,963)		$ 447,431
Distribution of deferred directors' compensation, shares						27,216
Increase in deferred directors' compensation charged to expense	266,182			266,182
Balances at Jun. 30, 2017	115,986,251	$ 280,938	2,531,822	3,367,432	112,962,754	$ (3,156,695)
Balances, shares at Jun. 30, 2017		16,863,004
Balances, Treasury shares at Jun. 30, 2017						(191,988)
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)	$ 14,080,022				14,080,022
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	501,626		501,626
Dividends ($.12 per share)	(2,023,500)				(2,023,500)
Distribution of restricted stock to officers and directors	819	$ 14	(808,357)			$ 809,162
Distribution of restricted stock to officers and directors, shares		852				48,325
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	233,573			233,573
Balances at Jun. 30, 2018	$ 129,234,714	$ 281,495	$ 2,690,834	$ 2,882,263	$ 125,386,738	$ (2,006,616)
Balances, shares at Jun. 30, 2018		16,896,455
Balances, Treasury shares at Jun. 30, 2018	(117,946)					(117,946)