Condensed Statements Of Cash Flows - USD ($)	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Activities
Net income (loss)	$ 14,855,115	$ 1,232,041
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	9,516,902	8,939,918
Impairment	0	10,788
Provision for deferred income taxes	(12,771,000)	(76,000)
Gain from leasing fee mineral acreage	(595,946)	(3,171,490)
Proceeds from leasing fee mineral acreage	610,552	3,191,075
Net (gain) loss on sales of assets	466,128	87,161
Directors' deferred compensation expense	170,826	176,368
Fair value of derivative contracts	2,486,518	(384,566)
Restricted stock awards	347,838	317,633
Other	(1,337)	(835)
Cash provided (used) by changes in assets and liabilities:
Oil, NGL and natural gas sales receivables	1,110,368	136,669
Other current assets	(87,495)	81,325
Accounts payable	(73,066)	(203,053)
Income taxes receivable	(302,370)	(792,488)
Other non-current assets	(66,364)
Accrued liabilities	(306,687)	(195,981)
Total adjustments	504,867	8,116,524
Net cash provided by operating activities	15,359,982	9,348,565
Investing Activities
Capital expenditures	(6,544,481)	(7,721,254)
Investments in partnerships	7,493	(17,220)
Proceeds from sales of assets	1,129,705	718,700
Net cash provided (used) by investing activities	(5,407,283)	(7,019,774)
Financing Activities
Borrowings under debt agreement	10,596,451	7,038,699
Payments of loan principal	(19,318,671)	(7,538,699)
Purchases of treasury stock	(272,100)	(407,677)
Payments of dividends	(1,347,608)	(1,340,656)
Net cash provided (used) by financing activities	(10,341,928)	(2,248,333)
Increase (decrease) in cash and cash equivalents	(389,229)	80,458
Cash and cash equivalents at beginning of period	557,791	471,213
Cash and cash equivalents at end of period	168,562	551,671
Supplemental Schedule of Noncash Investing and Financing Activities:
Additions to asset retirement obligations	13,871	32,236
Gross additions to properties and equipment	5,556,196	10,867,308
Net (increase) decrease in accounts payable for properties and equipment additions	988,285	(3,146,054)
Capital expenditures and acquisitions	$ 6,544,481	$ 7,721,254