CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 5,542,590	$ 3,202,943
Adjustments to reconcile net income from operations to net cash flows from (used in) operating activities:
Depreciation	3,116,449	2,575,924
Amortization		41,667
Equity method investment earnings, net of tax	(183,579)
Impairment charges	485,270	2,873,269
Loss (gain) on sales of property and equipment	105,039	(13,775)
Equity-based compensation	1,085,287	1,299,792
Deferred income taxes	(16,798)	40,572
Provision for losses on doubtful accounts	(21,000)	21,000
Inventory allowance	(322,240)	560,610
Changes in assets and liabilities:
Accounts receivable	(9,591,809)	6,742,225
Inventories	3,693,984	(24,034,512)
Prepaid and other current assets	4,794,469	(2,207,684)
Other assets	(110,207)	28,214
Accounts payable	3,529,980	(2,247,262)
Accrued expenses and accrued wages, salaries and bonuses	1,353,113	(262,330)
Other long-term liabilities	885,230	3,956
Income taxes payable and receivable	857,270	(78,266)
Net cash flows from (used in) operating activities	15,203,048	(11,453,657)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(3,356,573)	(4,438,280)
Proceeds from sales of property and equipment	43,600	57,200
Investment in equity method investee	(6,500,000)
Issuance of note receivable	(3,500,000)
Net cash flows from (used in) investing activities	(13,312,973)	(4,381,080)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings under revolving credit facility	1,515,476,055	1,427,544,804
Repayments under revolving credit facility	(1,513,881,087)	(1,402,596,687)
Principal payments on long-term debt	(532,747)	(1,096,306)
Proceeds from exercise of stock options	25,750
Repurchase of common stock	(2,029,694)	(7,507,103)
Dividends on common stock	(594,653)	(636,576)
Settlement and withholdings of equity-based awards	(30,208)	(56,335)
Net cash flows from (used in) financing activities	(1,566,584)	15,651,797
Net change in cash	323,491	(182,940)
Cash, beginning of period	337,704	520,644
Cash, end of period	661,195	337,704
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	1,743,098	1,561,531
Cash paid during the period for income taxes	1,302,528	1,646,694
Supplemental disclosure of non-cash information:
Equipment acquisitions classified in accounts payable		69,253
Issuance of common stock in connection with the vesting and exercise of equity-based awards	$ 990,653	$ 1,005,792