Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2019	Mar. 31, 2018
Numerator:
Income from continuing operations, net of tax	$ 1,012		$ 1,061		$ 1,260	$ 2,762
(Loss) income from discontinued operations, net of tax	(6,647)		1,774		(9,267)	6,525
Net (loss) income	$ (5,635)	$ (2,372)	$ 2,835	$ 6,452	$ (8,007)	$ 9,287
Denominator:
Weighted-average shares used to compute basic EPS (in shares)	14,228		14,891		14,224	14,835
Common stock equivalents (in shares)	30		263		31	388
Weighted-average shares used to compute diluted EPS (in shares)	14,258		15,154		14,255	15,223
Basic income per share from continuing operations (USD per share)	$ 0.07		$ 0.07		$ 0.09	$ 0.19
Basic (loss) income per share from discontinued operations (USD per share)	(0.47)		0.12		(0.65)	0.44
Net (loss) income per basic share (USD per share)	(0.40)		0.19		(0.56)	0.63
Diluted income per share from continuing operations (USD per share)	0.07		0.07		0.09	0.18
Diluted (loss) income per share from discontinued operations (USD per share)	(0.47)		0.12		(0.65)	0.43
Net (loss) income per diluted share (USD per share)	$ (0.40)		$ 0.19		$ (0.56)	$ 0.61
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	1,248		422		1,220	296