STOCKHOLDERS’ EQUITY - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Number of Shares
Outstanding, beginning balance (in shares)	781,092	816,717	1,162,505
Granted (in shares)	0	0	0
Exercised (in shares)	(98,952)	(35,625)	(329,878)
Canceled (in shares)	(30,871)	0	(15,910)
Outstanding, ending balance (in shares)	651,269	781,092	816,717	1,162,505
Weighted- Average Exercise Price
Outstanding, beginning balance (in dollars per share)	$ 7.46	$ 7.42	$ 7.51
Granted (in dollars per share)	0	0	0
Exercised (in dollars per share)	7.44	6.68	7.63
Canceled (in dollars per share)	9.49	0	9.41
Outstanding, ending balance (in dollars per share)	$ 7.37	$ 7.46	$ 7.42	$ 7.51
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract]
Vested and expected to vest (in shares)	651,269
Exercisable (in shares)	647,884
Vested and expected to vest, weighted-average exercise price (in dollars per share)	$ 7.37
Exercisable, weighted-average exercise price (in dollars per share)	$ 7.35
Outstanding, weighted-average remaining contractual terms (in years)	3 years 7 months 6 days	3 years 8 months 12 days	5 years 9 months 18 days	6 years 1 month 6 days
Vested and expected to vest, weighted-average remaining contractual term (in years)	3 years 7 months 6 days
Exercisable, weighted-average remaining contractual term (in years)	3 years 7 months 6 days
Outstanding, aggregate intrinsic value	$ 2,185	$ 1,512	$ 9,046	$ 6,081
Exercised, aggregate intrinsic value	338	$ 279	$ 2,670
Vested and expected to vest, aggregate intrinsic value	2,185
Exercisable, aggregate intrinsic value	$ 2,181