Earnings (Loss) Per Share (Details) - USD ($)	3 Months Ended								12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Net income (loss)	$ 555,647	$ (775,093)	$ 1,070,176	$ 13,784,939	$ 1,039,134	$ 1,260,758	$ 3,470,433	$ (2,238,392)	$ 14,635,669	$ 3,531,933	$ (10,286,884)
Denominator for basic and diluted earnings per share - Weighted average shares (including for 2018, 2017 and 2016, unissued, vested directors' shares of 205,736, 253,603 and 263,057, respectively)									16,952,664	16,900,185	16,840,856