Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Sep. 30, 2018
Accounts receivable:
Allowance for doubtful accounts	$ 267	$ 548
Shareholders’ equity:
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	34,766,000	34,487,000
Common stock, shares outstanding (in shares)	27,856,000	27,577,000
Treasury stock, shares held (in shares)	6,910,000	6,910,000