Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2021	Sep. 30, 2020
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 634	$ 389
Property and equipment, accumulated depreciation	$ 17,834	$ 14,555
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares issued	35,417,715	34,082,406
Common stock, shares outstanding	35,417,715	34,082,406
Treasury stock (in shares)	1,587,199	547,508