Summary of Significant Accounting Policies - Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Net loss	$ (2,038)	$ (1,657)	$ (2,949)	$ (4,266)
Weighted-average common shares outstanding (basic and diluted) (in shares)	5,535,000	5,479,000	5,519,000	5,473,000
Net loss per share - basic and diluted (in dollars per share)	$ (0.37)	$ (0.30)	$ (0.53)	$ (0.78)
Anti-dilutive weighted-average common shares excluded from calculation of diluted earnings per share (in shares)	140,000	120,000	125,000	90,000
Restricted Stock
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Anti-dilutive weighted-average common shares excluded from calculation of diluted earnings per share (in shares)	0	0	0	0