Nature of Operations and Summary of Significant Accounting Policies - Calculation of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Net income	$ 3,124	$ 2,167
Weighted-average shares outstanding - basic (in shares)	44,788	42,476
Common stock equivalents (in shares)	1,367	1,421
Weighted-average shares outstanding - diluted (in shares)	46,155	43,897
Net income per share:
Basic (in dollars per share)	$ 0.07	$ 0.05
Diluted (in dollars per share)	$ 0.07	$ 0.05