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, 2019	$ 122,516	$ 675	$ 10,740	$ 396	$ 110,705
Beginning balance, shares at Sep. 30, 2019	13,504
Net (loss) income	$ 4,069				4,069
Other comprehensive income, net of tax	1,073			1,073
Issuance of common stock	$ 218	7	211
Issuance of common stock, shares	133
Common stock options exercised, net	$ 951	2	949
Common stock options exercised, net, shares	53
Purchase of common stock to pay employee taxes	$ (2,281)	(2)	(2,279)
Purchase of common stock to pay employee taxes, shares	(45)
Stock-based compensation	$ 4,037		4,037
Ending balance at Jun. 30, 2020	$ 130,583	682	13,658	1,469	114,774
Ending balance, shares at Jun. 30, 2020	13,645
Beginning balance at Mar. 31, 2020	$ 124,966	680	11,481	490	112,315
Beginning balance, shares at Mar. 31, 2020	13,609
Net (loss) income	$ 2,459				2,459
Other comprehensive income, net of tax	$ 979			979
Issuance of common stock, shares	3
Common stock options exercised, net	$ 851	2	849
Common stock options exercised, net, shares	33
Purchase of common stock to pay employee taxes	$ (12)		(12)
Stock-based compensation	1,340		1,340
Ending balance at Jun. 30, 2020	$ 130,583	682	13,658	1,469	114,774
Ending balance, shares at Jun. 30, 2020	13,645
Beginning balance at Sep. 30, 2020	$ 131,055	684	15,369	3,174	111,828
Beginning balance, shares at Sep. 30, 2020	13,672
Net (loss) income	$ 4,526				4,526
Other comprehensive income, net of tax	585			585
Issuance of common stock	$ 297	5	292
Issuance of common stock, shares	91
Common stock options exercised, net	$ 2,330	6	2,324
Common stock options exercised, net, shares	127
Purchase of common stock to pay employee taxes	$ (2,279)	(1)	(2,278)
Purchase of common stock to pay employee taxes, shares	(18)
Stock-based compensation	$ 4,318		4,318
Ending balance at Jun. 30, 2021	$ 140,832	694	20,025	3,759	116,354
Ending balance, shares at Jun. 30, 2021	13,872
Beginning balance at Mar. 31, 2021	$ 142,081	693	18,516	3,231	119,641
Beginning balance, shares at Mar. 31, 2021	13,868
Net (loss) income	$ (3,287)				(3,287)
Other comprehensive income, net of tax	528			528
Issuance of common stock	$ 1	1
Issuance of common stock, shares	2
Common stock options exercised, net	$ 90		90
Common stock options exercised, net, shares	2
Purchase of common stock to pay employee taxes	$ (37)		(37)
Stock-based compensation	1,456		1,456
Ending balance at Jun. 30, 2021	$ 140,832	$ 694	$ 20,025	$ 3,759	$ 116,354
Ending balance, shares at Jun. 30, 2021	13,872