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	(22)				(22)
Other comprehensive income (loss), net of tax	1,796			1,796
Issuance of common stock	166	$ 6	160
Issuance of common stock, shares		127
Common stock options exercised, net	217	$ 8	209
Common stock options exercised, net, shares		171
Purchase of common stock to pay employee taxes	(2,361)	$ (7)	(2,354)
Purchase of common stock to pay employee taxes, shares		(146)
Stock-based compensation	2,003		2,003
Ending balance at Mar. 31, 2018	113,356	$ 662	5,431	5,213	102,050
Ending balance, shares at Mar. 31, 2018		13,247
Beginning balance at Dec. 31, 2017	110,547	$ 660	5,337	4,034	100,516
Beginning balance, shares at Dec. 31, 2017		13,196
Net (loss) income	1,534				1,534
Other comprehensive income (loss), net of tax	1,179			1,179
Issuance of common stock	166		166
Issuance of common stock, shares		3
Common stock options exercised, net	62	$ 8	54
Common stock options exercised, net, shares		159
Purchase of common stock to pay employee taxes	(1,231)	$ (6)	(1,225)
Purchase of common stock to pay employee taxes, shares		(111)
Stock-based compensation	1,099		1,099
Ending balance at Mar. 31, 2018	113,356	$ 662	5,431	5,213	102,050
Ending balance, shares at Mar. 31, 2018		13,247
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	2,572				2,572
Other comprehensive income (loss), net of tax	(1,274)			(1,274)
Issuance of common stock	209	$ 6	203
Issuance of common stock, shares		134
Common stock options exercised, net	55	$ 0	55
Common stock options exercised, net, shares		2
Purchase of common stock to pay employee taxes	(2,547)	$ (2)	(2,545)
Purchase of common stock to pay employee taxes, shares		(45)
Stock-based compensation	2,190		2,190
Ending balance at Mar. 31, 2019	115,313	$ 674	7,510	1,444	105,685
Ending balance, shares at Mar. 31, 2019		13,489
Beginning balance at Dec. 31, 2018	113,621	$ 674	6,340	2,184	104,423
Beginning balance, shares at Dec. 31, 2018		13,483
Net (loss) income	1,262				1,262
Other comprehensive income (loss), net of tax	(740)			(740)
Issuance of common stock	209		209
Issuance of common stock, shares		6
Common stock options exercised, net	19		19
Common stock options exercised, net, shares		1
Purchase of common stock to pay employee taxes	(17)		(17)
Purchase of common stock to pay employee taxes, shares		(1)
Stock-based compensation	959		959
Ending balance at Mar. 31, 2019	$ 115,313	$ 674	$ 7,510	$ 1,444	$ 105,685
Ending balance, shares at Mar. 31, 2019		13,489