Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]
Beginning balance at Sep. 30, 2017	$ 111,557	$ 655	$ 5,413	$ 3,417	$ 102,072
Beginning balance, shares at Sep. 30, 2017		13,095
Net (loss) income	(2,704)				(2,704)
Other comprehensive income (loss), net of tax	(435)			(435)
Issuance of common stock	166	$ 6	160
Issuance of common stock, shares		127
Common stock options exercised, net	1,234	$ 19	1,215
Common stock options exercised, net, shares		385
Purchase of common stock to pay employee taxes	(4,370)	$ (13)	(4,357)
Purchase of common stock to pay employee taxes, shares		(258)
Stock-based compensation	3,297		3,297
Ending balance at Jun. 30, 2018	108,745	$ 667	5,728	2,982	99,368
Ending balance, shares at Jun. 30, 2018		13,349
Beginning balance at Mar. 31, 2018	113,356	$ 662	5,431	5,213	102,050
Beginning balance, shares at Mar. 31, 2018		13,247
Net (loss) income	(2,682)				(2,682)
Other comprehensive income (loss), net of tax	(2,231)			(2,231)
Issuance of common stock			0
Issuance of common stock, shares		1
Common stock options exercised, net	1,016	$ 11	1,005
Common stock options exercised, net, shares		214
Purchase of common stock to pay employee taxes	(2,007)	$ (6)	(2,001)
Purchase of common stock to pay employee taxes, shares		(113)
Stock-based compensation	1,293		1,293
Ending balance at Jun. 30, 2018	108,745	$ 667	5,728	2,982	99,368
Ending balance, shares at Jun. 30, 2018		13,349
Beginning balance at Sep. 30, 2018	108,610	$ 670	7,607	2,718	97,615
Beginning balance, shares at Sep. 30, 2018		13,398
Net impact from adoption of ASC Topic 606 (Note 2)	5,498				5,498
Net (loss) income	4,038				4,038
Other comprehensive income (loss), net of tax	(741)			(741)
Issuance of common stock	210	$ 7	203
Issuance of common stock, shares		135
Common stock options exercised, net	67	$ 0	67
Common stock options exercised, net, shares		3
Purchase of common stock to pay employee taxes	(2,559)	$ (2)	(2,557)
Purchase of common stock to pay employee taxes, shares		(46)
Stock-based compensation	3,509		3,509
Ending balance at Jun. 30, 2019	118,632	$ 675	8,829	1,977	107,151
Ending balance, shares at Jun. 30, 2019		13,490
Beginning balance at Mar. 31, 2019	115,313	$ 674	7,510	1,444	105,685
Beginning balance, shares at Mar. 31, 2019		13,489
Net (loss) income	1,466				1,466
Other comprehensive income (loss), net of tax	533			533
Issuance of common stock	1	$ 1
Issuance of common stock, shares		1
Common stock options exercised, net	12		12
Common stock options exercised, net, shares		1
Purchase of common stock to pay employee taxes	(12)		(12)
Purchase of common stock to pay employee taxes, shares		(1)
Stock-based compensation	1,319		1,319
Ending balance at Jun. 30, 2019	$ 118,632	$ 675	$ 8,829	$ 1,977	$ 107,151
Ending balance, shares at Jun. 30, 2019		13,490