CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Beginning Balance (in shares) at Sep. 30, 2019		40,367,000
Beginning Balance at Sep. 30, 2019	$ 107,333	$ 40	$ 132,160		$ (20,806)	$ (4,061)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	580,861	581,000
Exercise of stock options	$ 3,572	$ 1	3,571
Settlement of restricted stock units (in shares)		819,000
Settlement of restricted stock units	0	$ 1	(1)
Issuance of common stock under employee stock purchase plan (in shares)		150,000
Issuance of common stock under employee stock purchase plan	1,237		1,237
Stock-based compensation expense	9,551		9,551
Repurchase and retirements of common stock (in shares)		(137,000)
Repurchases and retirements of common stock	(1,002)				(1,002)
Components of other comprehensive income (loss)
Net income	7,814				7,814
Currency translation adjustment	3,635					3,635
Change in unrealized gain (loss) on investments	103					103
Other comprehensive income (loss)	11,552
Ending Balance (in shares) at Sep. 30, 2020		41,780,000		0
Ending Balance at Sep. 30, 2020	$ 132,243	$ 42	146,518	$ 0	(13,994)	(323)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	329,878	330,000
Exercise of stock options	$ 2,516	$ 0	2,516
Settlement of restricted stock units (in shares)		1,066,000
Settlement of restricted stock units	0	$ 1	(1)
Issuance of common stock under employee stock purchase plan (in shares)		129,000
Issuance of common stock under employee stock purchase plan	1,519		1,519
Acquisition-related shares issued (in shares)		867,000
Acquisition-related shares issued	13,943	$ 1	13,942
Stock-based compensation expense	11,532		11,532
Sale of convertible senior notes warrants	23,909		23,909
Repurchase and retirements of common stock (in shares)		(3,000)		(8,000)
Repurchases and retirements of common stock	(190)			$ (140)	(50)
Components of other comprehensive income (loss)
Net income	7,978				7,978
Currency translation adjustment	(455)					(455)
Change in unrealized gain (loss) on investments	(165)					(165)
Other comprehensive income (loss)	$ 7,358
Ending Balance (in shares) at Sep. 30, 2021	44,168,745	44,169,000		(8,000)
Ending Balance at Sep. 30, 2021	$ 192,830	$ 44	199,935	$ (140)	(6,066)	(943)
Components of other comprehensive income (loss)
Net income	3,559
Currency translation adjustment	(3,129)
Change in unrealized gain (loss) on investments	(1,098)
Other comprehensive income (loss)	$ (668)
Ending Balance (in shares) at Mar. 31, 2022	44,344,361
Ending Balance at Mar. 31, 2022	$ 184,892
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)
Components of other comprehensive income (loss)
Net income	3,344
Currency translation adjustment	(16,724)
Change in unrealized gain (loss) on investments	(189)
Other comprehensive income (loss)	$ (13,569)
Ending Balance (in shares) at Jun. 30, 2022	44,396,263
Ending Balance at Jun. 30, 2022	$ 175,712
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)	35,625	35,000
Exercise of stock options	$ 238		238
Settlement of restricted stock units (in shares)		1,075,000
Settlement of restricted stock units	0	$ 1	(1)
Issuance of common stock under employee stock purchase plan (in shares)		129,000
Issuance of common stock under employee stock purchase plan	1,487		1,487
Acquisition-related shares issued (in shares)		203,000
Acquisition-related shares issued	1,836		1,836
Stock-based compensation expense	13,346		13,346
Repurchase and retirements of common stock (in shares)		(931,000)		8,000
Repurchases and retirements of common stock	(15,176)	$ (1)	(348)	$ 140	(14,967)
Components of other comprehensive income (loss)
Net income	3,032				3,032
Currency translation adjustment	(27,559)					(27,559)
Change in unrealized gain (loss) on investments	283					283
Other comprehensive income (loss)	$ (24,244)
Ending Balance (in shares) at Sep. 30, 2022	44,680,429	44,680,000		0
Ending Balance at Sep. 30, 2022	$ 170,317	$ 44	216,493	$ 0	(18,001)	(28,219)
Beginning Balance (in shares) at Mar. 31, 2022	44,344,361
Beginning Balance at Mar. 31, 2022	$ 184,892
Components of other comprehensive income (loss)
Net income	(215)
Currency translation adjustment	(13,595)
Change in unrealized gain (loss) on investments	909
Other comprehensive income (loss)	$ (12,901)
Ending Balance (in shares) at Jun. 30, 2022	44,396,263
Ending Balance at Jun. 30, 2022	$ 175,712
Components of other comprehensive income (loss)
Net income	$ (311)
Ending Balance (in shares) at Sep. 30, 2022	44,680,429	44,680,000		0
Ending Balance at Sep. 30, 2022	$ 170,317	$ 44	$ 216,493	$ 0	$ (18,001)	$ (28,219)