CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Cumulative-effect adjustment for adoption of ASC 842	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Deficit Cumulative-effect adjustment for adoption of ASC 842
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member
Beginning Balance (in shares) at Sep. 30, 2019			12,036,000	0
Beginning Balance at Sep. 30, 2019	$ 45,571	$ (2)	$ 12	$ 0	$ 85,114	$ (39,555)	$ (2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Expense related to director restricted stock unit (in shares)			90,000
Expense related to director restricted stock unit	260				260
Expense related to employee stock-based compensation	306				306
Repurchases of common stock (in shares)				28,000
Repurchases of common stock	(113)			$ (113)
Cancellation of common stock (in shares)			(117,000)	(28,000)
Cancellation of common stock	(98)			$ 113	(211)
Exercise of stock options (in shares)			345,000
Exercise of stock options	27				27
Net income	5,752					5,752
Ending Balance (in shares) at Jun. 30, 2020			12,354,000	0
Ending Balance at Jun. 30, 2020	51,703		$ 12	$ 0	85,496	(33,805)
Beginning Balance (in shares) at Mar. 31, 2020			12,354,000	0
Beginning Balance at Mar. 31, 2020	49,397		$ 12	$ 0	85,314	(35,929)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Expense related to director restricted stock unit	87				87
Expense related to employee stock-based compensation	95				95
Net income	2,124					2,124
Ending Balance (in shares) at Jun. 30, 2020			12,354,000	0
Ending Balance at Jun. 30, 2020	$ 51,703		$ 12	$ 0	85,496	(33,805)
Beginning Balance (in shares) at Sep. 30, 2020	12,404,000		12,404,000	0
Beginning Balance at Sep. 30, 2020	$ 53,437		$ 12	$ 0	85,868	(32,443)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Expense related to director restricted stock unit (in shares)			78,000
Expense related to director restricted stock unit	349				349
Expense related to employee stock-based compensation	$ 968				968
Exercise of stock options (in shares)	63,000		63,000
Exercise of stock options	$ 231		$ 1		230
Net income	$ 7,261					7,261
Ending Balance (in shares) at Jun. 30, 2021	12,545,000		12,545,000	0
Ending Balance at Jun. 30, 2021	$ 62,246		$ 13	$ 0	87,415	(25,182)
Beginning Balance (in shares) at Mar. 31, 2021			12,545,000	0
Beginning Balance at Mar. 31, 2021	58,893		$ 13	$ 0	86,942	(28,062)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Expense related to director restricted stock unit	117				117
Expense related to employee stock-based compensation	356				356
Exercise of stock options	0
Net income	$ 2,880					2,880
Ending Balance (in shares) at Jun. 30, 2021	12,545,000		12,545,000	0
Ending Balance at Jun. 30, 2021	$ 62,246		$ 13	$ 0	$ 87,415	$ (25,182)