Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2021	Sep. 30, 2020
LIABILITIES AND STOCKHOLDERS’ EQUITY
Allowances for accounts receivable	$ 292	$ 358
Unamortized debt issuance expense	$ 9,444	$ 10,891
Preferred stock, par value (in USD per share)	$ 0.01	$ 0.01
Preferred stock authorized (in shares)	5,000,000	5,000,000
Preferred stock issued (in shares)	0	0
Common stock, par value (in USD per share)	$ 0.001	$ 0.001
Common stock authorized (in shares)	63,000,000	63,000,000
Common stock issued (in shares)	31,293,798	31,012,326
Common stock outstanding (in shares)	31,293,798	31,012,326