Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Sep. 30, 2019
Accounts receivable:
Allowance for doubtful accounts	$ 303	$ 148
Shareholders' equity:
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	36,318,000	35,803,000
Common stock, shares outstanding (in shares)	29,408,000	28,893,000
Treasury stock, shares held (in shares)	6,910,000	6,910,000