Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning balance (in shares) at Sep. 30, 2018		27,577,000
Shares of common stock
Stock-based compensation (in shares)		307,000
Stock option exercises (in shares)		1,000
Issuance of common stock for acquisition (in shares)		811,000
Issuance of restricted stock units (shares)		0
Issuance of common stock - ESPP (in shares)		197,000
Sale of common stock (in shares)		0
Ending balance (in shares) at Sep. 30, 2019		28,893,000
Balance, beginning of period at Sep. 30, 2018		$ 734,066	$ (47,721)	$ 885	$ (580,425)
Shares of common stock
Stock-based compensation		2,607
Stock option exercises		1
Tax withholding paid on behalf of employees for stock-based awards		(203)
Issuance of common stock for acquisition		2,951
Issuance of restricted stock units		0
Issuance of common stock - ESPP		504
Sale of common stock, net of offering costs		0
Translation adjustment	$ 65			65
Net income (loss)	(35,984)				(35,984)
Balance, end of period at Sep. 30, 2019	$ 76,746	$ 739,926	(47,721)	950	(616,409)
Shares of common stock
Stock-based compensation (in shares)		309,000
Stock option exercises (in shares)		1,000
Issuance of common stock for acquisition (in shares)		0
Issuance of restricted stock units (shares)		116,000
Issuance of common stock - ESPP (in shares)		231,000
Sale of common stock (in shares)		0
Ending balance (in shares) at Sep. 30, 2020	29,551,000	29,550,000
Shares of common stock
Stock-based compensation		$ 3,517
Stock option exercises		2
Tax withholding paid on behalf of employees for stock-based awards		(111)
Issuance of common stock for acquisition		0
Issuance of restricted stock units		410
Issuance of common stock - ESPP		617
Sale of common stock, net of offering costs		0
Translation adjustment	$ (32)			(32)
Net income (loss)	(7,000)				(7,000)
Balance, end of period at Sep. 30, 2020	$ 74,149	$ 744,361	(47,721)	918	(623,409)
Shares of common stock
Stock-based compensation (in shares)		572,000
Stock option exercises (in shares)	15,025	15,000
Issuance of common stock for acquisition (in shares)		0
Issuance of restricted stock units (shares)		0
Issuance of common stock - ESPP (in shares)		192,000
Sale of common stock (in shares)		6,655,000
Ending balance (in shares) at Sep. 30, 2021	36,984,000	36,984,000
Shares of common stock
Stock-based compensation		$ 4,180
Stock option exercises		77
Tax withholding paid on behalf of employees for stock-based awards		(260)
Issuance of common stock for acquisition		0
Issuance of restricted stock units		0
Issuance of common stock - ESPP		767
Sale of common stock, net of offering costs		33,141
Translation adjustment	$ (231)			(231)
Net income (loss)	25,643				25,643
Balance, end of period at Sep. 30, 2021	$ 137,466	$ 782,266	$ (47,721)	$ 687	$ (597,766)