GOODWILL AND OTHER INTANGIBLES - Narrative (Details)	3 Months Ended				9 Months Ended
	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Sep. 30, 2019 reporting_unit	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 2,381,000			$ 2,506,000	$ 7,177,000	$ 7,436,000
Estimated amortization expense, remainder of 2020	2,416,000				2,416,000
Estimated amortization expense, fiscal 2021	9,387,000				9,387,000
Estimated amortization expense, fiscal 2022	9,387,000				9,387,000
Estimated amortization expense, fiscal 2023	9,234,000				9,234,000
Estimated amortization expense, fiscal 2024	9,208,000				9,208,000
Estimated amortization expense, fiscal 2025	9,208,000				9,208,000
Estimated amortization expense, thereafter	$ 82,860,000				$ 82,860,000
Number of reporting units for goodwill impairment testing | reporting_unit			3
Goodwill impairment		$ 0
Indefinite-lived intangible asset (excluding goodwill) impairment		$ 0