Summary of Significant Accounting Policies - Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Income (loss)	$ 3,260	$ (1,258)	$ 1,919	$ (2,540)
Weighted-average common shares outstanding (basic and diluted) (in shares)	5,679,000	5,561,000	5,645,000	5,548,000
Effect of dilutive securities:
Weighted-average common shares outstanding (basic and diluted) (in shares)	5,770,000	5,561,000	5,748,000	5,548,000
Net loss per share – basic:
Net income (loss) per share – basic (in dollars per share)	$ 0.57	$ (0.23)	$ 0.34	$ (0.46)
Net income (loss) per share – diluted (in dollars per share)	$ 0.57	$ (0.23)	$ 0.33	$ (0.46)
Anti-dilutive weighted-average common shares excluded from calculation of diluted earnings per share (in shares)	215,000	214,000	147,000	200,000
Restricted shares
Effect of dilutive securities:
Restricted shares (in shares)	89,000	0	102,000	0
Net loss per share – basic:
Anti-dilutive weighted-average common shares excluded from calculation of diluted earnings per share (in shares)			0
Performance shares
Effect of dilutive securities:
Restricted shares (in shares)	2,000	0	1,000	0