EARNINGS PER COMMON SHARE (Details) - USD ($)	3 Months Ended												12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2015
Basic income per common share:
Net Income	$ 1,744,000	$ 9,787,000	$ 32,142,000	$ 1,244,000	$ 6,006,000	$ 8,873,000	$ 14,283,000	$ 4,058,000	$ 4,639,000	$ 4,640,000	$ 5,181,000	$ 3,595,000	$ 44,917,000		$ 33,220,000		$ 18,055,000
Weighted average common shares outstanding (in shares)													$ 9,247,092		$ 8,443,956		$ 6,730,086
Basic income per common share (in dollars per share)	$ 0.19	$ 1.05	$ 3.44	$ 0.14	$ 0.70	$ 1.04	$ 1.68	$ 0.49	$ 0.64	$ 0.67	$ 0.79	$ 0.58	$ 4.86	[1]	$ 3.93	[1]	$ 2.68	[1]
Diluted income per common share:
Net income	$ 1,744,000	$ 9,787,000	$ 32,142,000	$ 1,244,000	$ 6,006,000	$ 8,873,000	$ 14,283,000	$ 4,058,000	$ 4,639,000	$ 4,640,000	$ 5,181,000	$ 3,595,000	$ 44,917,000		$ 33,220,000		$ 18,055,000
Weighted average common shares outstanding (in shares)													9,247,092		8,443,956		6,730,086
Outstanding options - based upon the two-class method (in shares)													$ 55,652		$ 53,390		$ 61,499
Weighted average diluted common shares outstanding (in shares)													9,302,744		8,497,346		6,791,585
Diluted (in dollars per share)	$ 0.19	$ 1.04	$ 3.42	$ 0.14	$ 0.70	$ 1.04	$ 1.67	$ 0.49	$ 0.63	$ 0.66	$ 0.78	$ 0.58	$ 4.83	[1]	$ 3.91	[1]	$ 2.66	[1]
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded from computing diluted EPS (in shares)																	28,891
Accounting Standards Update 2015-06 [Member]
Basic income per common share:
Basic income per common share (in dollars per share)															3.93
Diluted income per common share:
Diluted (in dollars per share)															3.91
Scenario, Previously Reported [Member] | Accounting Standards Update 2015-06 [Member]
Basic income per common share:
Basic income per common share (in dollars per share)															3.95
Diluted income per common share:
Diluted (in dollars per share)															$ 3.92

[1] See Reclassification and Revision of Prior Period Balances under Note 1 Summary of Significant Accounting Policies for additional information describing adjustments made to the Company's EPS calculation. Basic EPS for the fiscal year ended September 30, 2016 of $3.95 was corrected to $3.93 and diluted EPS of $3.92 was corrected to $3.91.