CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock Outstanding	Additional Paid-In Capital	Treasury Stock	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Beginning Balance (in shares) at Sep. 30, 2020		41,780,000
Beginning Balance at Sep. 30, 2020	$ 132,243	$ 42	$ 146,518		$ (13,994)	$ (323)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)		241,000
Exercise of stock options	1,889		1,889
Settlement of restricted stock units (in shares)		647,000
Settlement of restricted stock units	0	$ 1	(1)
Stock-based compensation expense	2,747		2,747
Components of other comprehensive income:
Net income	2,167				2,167
Foreign currency translation adjustment	2,760					2,760
Unrealized holding loss on available for sale investments	(53)					(53)
Other comprehensive income	4,874
Ending Balance (in shares) at Dec. 31, 2020		42,668,000
Ending Balance at Dec. 31, 2020	$ 141,753	$ 43	151,153		(11,827)	2,384
Beginning Balance (in shares) at Sep. 30, 2021	44,168,745	44,169,000		(8,000)
Beginning Balance at Sep. 30, 2021	$ 192,830	$ 44	199,935	$ (140)	(6,066)	(943)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	9,375	9,000
Exercise of stock options	$ 25		25
Settlement of restricted stock units (in shares)		725,000
Settlement of restricted stock units	0	$ 1	(1)
Stock-based compensation expense	3,132		3,132
Repurchases and retirement of common stock (in shares)		(606,000)		8,000
Repurchases and retirements of common stock	(10,145)	$ (1)		$ 140	(10,284)
Components of other comprehensive income:
Net income	3,124				3,124
Foreign currency translation adjustment	(1,267)					(1,267)
Unrealized holding loss on available for sale investments	(270)					(270)
Other comprehensive income	$ 1,587
Ending Balance (in shares) at Dec. 31, 2021	44,296,771	44,297,000		0
Ending Balance at Dec. 31, 2021	$ 187,429	$ 44	$ 203,091	$ 0	$ (13,226)	$ (2,480)