CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ 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	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
Expense related to director restricted stock unit	173				173
Expense related to employee stock based compensation	211				211
Repurchases of common stock (in shares)				28
Repurchases of common stock	(113)			$ (113)
Cancellation of common stock (in shares)			(117)	(28)
Cancellation of common stock	(98)			$ 113	(211)
Exercise of stock options (in shares)			345
Exercise of stock options	27				27
Net income	3,628					3,628
Ending Balance (in shares) at Mar. 31, 2020			12,354	0
Ending Balance at Mar. 31, 2020	49,397		$ 12	$ 0	85,314	(35,929)
Beginning Balance (in shares) at Dec. 31, 2019			12,124	27
Beginning Balance at Dec. 31, 2019	47,145		$ 12	$ (111)	85,249	(38,005)
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
Repurchases of common stock (in shares)				1
Repurchases of common stock	(2)			$ (2)
Cancellation of common stock (in shares)			(95)	(28)
Cancellation of common stock	(4)			$ 113	(117)
Exercise of stock options (in shares)			325
Exercise of stock options	0
Net income	2,076					2,076
Ending Balance (in shares) at Mar. 31, 2020			12,354	0
Ending Balance at Mar. 31, 2020	$ 49,397		$ 12	$ 0	85,314	(35,929)
Beginning Balance (in shares) at Sep. 30, 2020	12,404		12,404	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
Expense related to director restricted stock unit	232				232
Expense related to employee stock based compensation	$ 612				612
Exercise of stock options (in shares)	63		63
Exercise of stock options	$ 231		$ 1		230
Net income	$ 4,381					4,381
Ending Balance (in shares) at Mar. 31, 2021	12,545		12,545	0
Ending Balance at Mar. 31, 2021	$ 58,893		$ 13	$ 0	86,942	(28,062)
Beginning Balance (in shares) at Dec. 31, 2020			12,544	0
Beginning Balance at Dec. 31, 2020	55,935		$ 13	$ 0	86,551	(30,629)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Expense related to director restricted stock unit	116				116
Expense related to employee stock based compensation	270				270
Exercise of stock options (in shares)			1
Exercise of stock options	5				5
Net income	$ 2,567					2,567
Ending Balance (in shares) at Mar. 31, 2021	12,545		12,545	0
Ending Balance at Mar. 31, 2021	$ 58,893		$ 13	$ 0	$ 86,942	$ (28,062)