CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Treasury Stock	Accumulated other comprehensive income	Accumulated deficit
Beginning balance (in shares) at Sep. 30, 2021		36,984
Shares of common stock
Stock-based compensation (in shares)		553
Stock option exercises (in shares)		6
Sale of common stock (in shares)		0
Ending balance (in shares) at Jun. 30, 2022		37,543
Balance, beginning of period at Sep. 30, 2021		$ 782,266	$ (47,721)	$ 687	$ (597,766)
Shares of common stock
Stock-based compensation		3,755
Stock option exercises		29
Tax withholding paid on behalf of employees for stock-based awards		(307)
Sale of common stock		0
Translation adjustment	$ 91			91
Net loss	(7,460)				(7,460)
Balance, end of period at Jun. 30, 2022	133,574	$ 785,743	(47,721)	778	(605,226)
Beginning balance (in shares) at Mar. 31, 2022		37,395
Shares of common stock
Stock-based compensation (in shares)		148
Stock option exercises (in shares)		0
Sale of common stock (in shares)		0
Ending balance (in shares) at Jun. 30, 2022		37,543
Balance, beginning of period at Mar. 31, 2022		$ 784,371	(47,721)	709	(597,577)
Shares of common stock
Stock-based compensation		1,523
Stock option exercises		0
Tax withholding paid on behalf of employees for stock-based awards		(151)
Sale of common stock		0
Translation adjustment	69			69
Net loss	(7,649)				(7,649)
Balance, end of period at Jun. 30, 2022	$ 133,574	$ 785,743	(47,721)	778	(605,226)
Beginning balance (in shares) at Sep. 30, 2022	37,591	37,591
Shares of common stock
Stock-based compensation (in shares)		1,107
Stock option exercises (in shares)		0
Sale of common stock (in shares)		15,455
Ending balance (in shares) at Jun. 30, 2023	54,153	54,153
Balance, beginning of period at Sep. 30, 2022		$ 787,347	(47,721)	1,301	(622,099)
Shares of common stock
Stock-based compensation		4,982
Stock option exercises		0
Tax withholding paid on behalf of employees for stock-based awards		(161)
Sale of common stock		15,437
Translation adjustment	$ (79)			79
Net loss	(33,778)
Balance, end of period at Jun. 30, 2023	$ 105,387	$ 807,605	(47,721)	1,380	(655,877)
Beginning balance (in shares) at Mar. 31, 2023		53,884
Shares of common stock
Stock-based compensation (in shares)		269
Stock option exercises (in shares)		0
Sale of common stock (in shares)		0
Ending balance (in shares) at Jun. 30, 2023	54,153	54,153
Balance, beginning of period at Mar. 31, 2023		$ 806,100	(47,721)	1,246	(646,020)
Shares of common stock
Stock-based compensation		1,713
Stock option exercises		0
Tax withholding paid on behalf of employees for stock-based awards		(17)
Sale of common stock		(191)
Translation adjustment	$ (134)			134
Net loss	(9,857)
Balance, end of period at Jun. 30, 2023	$ 105,387	$ 807,605	$ (47,721)	$ 1,380	$ (655,877)