GOODWILL AND INTANGIBLE ASSETS - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023	Sep. 30, 2023
Goodwill and Intangible Assets [Line Items]
Goodwill	$ 126,389,000		$ 126,389,000		$ 123,548,000
Goodwill impairment	0	$ 0	0	$ 0
Amortization of intangible assets	3,800,000	4,500,000	7,694,000	9,007,000
Impairment charges related to intangible assets	$ 0	$ 0	$ 0	$ 0
Minimum
Goodwill and Intangible Assets [Line Items]
Estimated useful lives of intangible assets (in years)	3 years		3 years
Maximum
Goodwill and Intangible Assets [Line Items]
Estimated useful lives of intangible assets (in years)	7 years		7 years