Earnings Per Share & Diluted Earnings Per Share - Reconciliation of Denominators of Basic and Diluted EPS Calculations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net income (loss) from continuing operations					$ (2,025)	$ (72)	$ (543)	$ (1,267)	$ 1,508	$ (3,907)	$ 3,135
Loss from discontinued operations, net of tax							$ (11,151)	$ (665)		(11,816)	(8,297)
Net income (loss)									$ 1,508	$ (15,723)	$ (5,162)
Denominator:
Weighted-average shares used to compute basic EPS	14,190	14,176	14,151	14,072	14,052	14,155	14,150	14,290	14,189	14,159	14,240
Common stock equivalents									151		35
Weighted-average shares used to compute diluted EPS	14,387	14,373	14,151	14,117	14,052	14,155	14,150	14,290	14,340	14,159	14,275
Basic income (loss) per share from continuing operations					$ (0.14)	$ (0.01)	$ (0.04)	$ (0.09)	$ 0.11	$ (0.28)	$ 0.22
Basic loss per share from discontinued operations							(0.79)	(0.05)		(0.83)	(0.58)
Net income (loss) per basic share	$ 0.05	$ 0.03	$ (0.02)	$ 0.05	(0.14)	(0.01)	(0.83)	(0.14)	0.11	(1.11)	(0.36)
Diluted income (loss) per share from continuing operations					(0.14)	(0.01)	(0.04)	(0.09)	0.11	(0.28)	0.22
Diluted loss per share from discontinued operations							(0.79)	(0.05)		(0.83)	(0.58)
Net income (loss) per diluted share	$ 0.05	$ 0.03	$ (0.02)	$ 0.05	$ (0.14)	$ (0.01)	$ (0.83)	$ (0.14)	$ 0.11	$ (1.11)	$ (0.36)