Summary of Significant Accounting Policies - Net Income (Loss) per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Income (loss)	$ (1,491)	$ 3,260	$ 1,502	$ 1,919
Weighted-average common shares outstanding (basic and diluted) (in shares)	5,777,000	5,679,000	5,735,000	5,645,000
Effect of dilutive securities:
Weighted-average common shares outstanding (basic and diluted) (in shares)	5,777,000	5,770,000	5,932,000	5,748,000
Net income (loss) per share
Net income (loss) per share – basic (in dollars per share)	$ (0.26)	$ 0.57	$ 0.26	$ 0.34
Net income (loss) per share – diluted (in dollars per share)	$ (0.26)	$ 0.57	$ 0.25	$ 0.33
Anti-dilutive weighted-average common shares excluded from calculation of diluted earnings per share (in shares)	411,000	215,000	217,000	147,000
Restricted shares
Effect of dilutive securities:
Restricted and performance shares (in shares)	0	89,000	144,000	102,000
Net income (loss) per share
Anti-dilutive weighted-average common shares excluded from calculation of diluted earnings per share (in shares)				0
Performance shares
Effect of dilutive securities:
Restricted and performance shares (in shares)	0	2,000	53,000	1,000