CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($)	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Common Stock, Beginning Balance (in shares) at Sep. 30, 2020		41,780,000
Beginning Balance at Sep. 30, 2020	$ 132,243,000	$ 42,000	$ 146,518,000		$ (13,994,000)	$ (323,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)		287,000
Exercise of stock options	2,198,000		2,198,000
Settlement of restricted stock units (in shares)		1,008,000
Settlement of restricted stock units	0	$ 1,000	(1,000)
Issuance of common stock under employee stock purchase plan (in shares)		77,000
Issuance of common stock under employee stock purchase plan	794,000		794,000
Acquisition-related shares issued (in shares)		867,000
Acquisition-related shares issued	13,943,000	$ 1,000	13,942,000
Stock-based compensation expense	8,582,000		8,582,000
Sale of convertible senior notes warrants	23,909,000		23,909,000
Net income	6,171,000				6,171,000
Components of other comprehensive income (loss):
Currency translation adjustment	859,000					859,000
Change in unrealized gain (loss) on investments	(175,000)					(175,000)
Common Stock, Ending Balance (in shares) at Jun. 30, 2021		44,019,000
Ending Balance at Jun. 30, 2021	188,524,000	$ 44,000	195,942,000		(7,823,000)	361,000
Common Stock, Beginning Balance (in shares) at Mar. 31, 2021		43,052,000
Beginning Balance at Mar. 31, 2021	167,729,000	$ 43,000	178,891,000		(10,808,000)	(397,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)		27,000
Exercise of stock options	241,000		241,000
Settlement of restricted stock units (in shares)		73,000
Settlement of restricted stock units	0
Acquisition-related shares issued (in shares)		867,000
Acquisition-related shares issued	13,944,000	$ 1,000	13,943,000
Stock-based compensation expense	2,867,000		2,867,000
Net income	2,985,000				2,985,000
Components of other comprehensive income (loss):
Currency translation adjustment	747,000					747,000
Change in unrealized gain (loss) on investments	11,000					11,000
Common Stock, Ending Balance (in shares) at Jun. 30, 2021		44,019,000
Ending Balance at Jun. 30, 2021	$ 188,524,000	$ 44,000	195,942,000		(7,823,000)	361,000
Common Stock, Beginning Balance (in shares) at Sep. 30, 2021	44,168,745	44,169,000
Treasury Stock, Beginning Balance (in shares) at Sep. 30, 2021				(8,000)
Beginning Balance at Sep. 30, 2021	$ 192,830,000	$ 44,000	199,935,000	$ (140,000)	(6,066,000)	(943,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	35,625	35,000
Exercise of stock options	$ 239,000		239,000
Settlement of restricted stock units (in shares)		1,015,000
Settlement of restricted stock units	0	$ 1,000	(1,000)
Issuance of common stock under employee stock purchase plan (in shares)		71,000
Issuance of common stock under employee stock purchase plan	923,000		923,000
Stock-based compensation expense	10,117,000		10,117,000
Repurchases and retirement of common stock (in shares)		(894,000)		(8,000)
Repurchases and retirement of common stock	(14,828,000)	$ (1,000)	(1,000)	$ 140,000	(14,966,000)
Net income	4,948,000				4,948,000
Components of other comprehensive income (loss):
Currency translation adjustment	(16,724,000)					(16,724,000)
Change in unrealized gain (loss) on investments	$ (189,000)					(189,000)
Common Stock, Ending Balance (in shares) at Jun. 30, 2022	44,396,263	44,396,000
Treasury Stock, Ending Balance (in shares) at Jun. 30, 2022				0
Ending Balance at Jun. 30, 2022	$ 177,316,000	$ 44,000	211,212,000	$ 0	(16,084,000)	(17,856,000)
Common Stock, Beginning Balance (in shares) at Mar. 31, 2022		44,344,000
Beginning Balance at Mar. 31, 2022	185,470,000	$ 44,000	207,491,000		(16,895,000)	(5,170,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)		10,000
Exercise of stock options	33,000		33,000
Settlement of restricted stock units (in shares)		42,000
Settlement of restricted stock units	0
Stock-based compensation expense	3,688,000		3,688,000
Net income	811,000				811,000
Components of other comprehensive income (loss):
Currency translation adjustment	(13,595,000)					(13,595,000)
Change in unrealized gain (loss) on investments	$ 909,000					909,000
Common Stock, Ending Balance (in shares) at Jun. 30, 2022	44,396,263	44,396,000
Treasury Stock, Ending Balance (in shares) at Jun. 30, 2022				0
Ending Balance at Jun. 30, 2022	$ 177,316,000	$ 44,000	$ 211,212,000	$ 0	$ (16,084,000)	$ (17,856,000)