Summary of Significant Accounting Policies - Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net income (loss)	$ 2,250	$ (7,370)	$ 4,168	$ (9,911)
Weighted-average common shares outstanding (basic and diluted) (in shares)	5,676,000	5,571,000	5,656,000	5,556,000
Effect of dilutive securities:
Weighted-average common shares outstanding (basic and diluted) (in shares)	5,807,000	5,571,000	5,768,000	5,556,000
Net loss per share – basic:
Net income (loss) per share – basic (in dollars per share)	$ 0.40	$ (1.32)	$ 0.74	$ (1.78)
Net income (loss) per share – diluted (in dollars per share)	$ 0.39	$ (1.32)	$ 0.72	$ (1.78)
Anti-dilutive weighted-average common shares excluded from calculation of diluted earnings per share (in shares)	306,000	214,000	200,000	200,000
Restricted shares
Effect of dilutive securities:
Restricted and performance shares (in shares)	115,000	0	106,000	0
Net loss per share – basic:
Anti-dilutive weighted-average common shares excluded from calculation of diluted earnings per share (in shares)		0		0
Performance shares
Effect of dilutive securities:
Restricted and performance shares (in shares)	16,000	0	6,000	0