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, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net (loss) income from continuing operations	$ (2,025)	$ (72)	$ (543)	$ (1,267)	$ 982	$ 893	$ 1,012	$ 248	$ (3,907)	$ 3,135	$ 6,631
Loss from discontinued operations, net of tax			$ (11,151)	$ (665)	$ (184)	$ 1,154	$ (6,647)	$ (2,620)	(11,816)	(8,297)	(1,326)
Net (loss) income									$ (15,723)	$ (5,162)	$ 5,305
Denominator:
Weighted-average shares used to compute basic EPS	14,052	14,155	14,150	14,290	14,266	14,245	14,228	14,220	14,159	14,240	14,833
Common stock equivalents										35	232
Weighted-average shares used to compute diluted EPS	14,052	14,155	14,150	14,290	14,304	14,316	14,258	14,252	14,159	14,275	15,065
Basic (loss) income per share from continuing operations	$ (0.14)	$ (0.01)	$ (0.04)	$ (0.09)	$ 0.07	$ 0.06	$ 0.07	$ 0.02	$ (0.28)	$ 0.22	$ 0.45
Basic loss per share from discontinued operations			(0.79)	(0.05)	(0.01)	0.08	(0.47)	(0.18)	(0.83)	(0.58)	(0.09)
Net (loss) income per basic share	(0.14)	(0.01)	(0.83)	(0.14)	0.06	0.14	(0.40)	(0.16)	(1.11)	(0.36)	0.36
Diluted (loss) income per share from continuing operations	(0.14)	(0.01)	(0.04)	(0.09)	0.07	0.06	0.07	0.02	(0.28)	0.22	0.44
Diluted loss per share from discontinued operations			(0.79)	(0.05)	(0.01)	0.08	(0.47)	(0.18)	(0.83)	(0.58)	(0.09)
Net (loss) income per diluted share	$ (0.14)	$ (0.01)	$ (0.83)	$ (0.14)	$ 0.06	$ 0.14	$ (0.40)	$ (0.16)	$ (1.11)	$ (0.36)	$ 0.35