LONG-TERM DEBT - Summary of long-term debt (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Sep. 30, 2021
Debt Instrument [Line Items]
Outstanding Balance	$ 1,595,560	$ 1,060,506
less: Current portion	(12,653)	(12,486)
Long-term debt	1,582,907	1,048,020
Original Issuer Premium (Discount)	(878)	315
Capitalized Fees & Expenses	(21,031)	(15,138)
Balance Sheet	1,573,651	1,045,683
less: Current portion	(12,653)	(12,486)
Long-term debt	1,560,998	1,033,197
Senior Notes due 2028
Debt Instrument [Line Items]
Outstanding Balance	974,775	1,000,000
Original Issuer Premium (Discount)	266	315
Capitalized Fees & Expenses	(10,939)	(13,293)
Balance Sheet	$ 964,102	$ 987,022
Coupon Interest Rate	5.75%	5.75%
Term Loan B due 2029
Debt Instrument [Line Items]
Outstanding Balance	$ 496,000
Original Issuer Premium (Discount)	(1,144)
Capitalized Fees & Expenses	(8,823)
Balance Sheet	486,033
Revolver due 2025
Debt Instrument [Line Items]
Outstanding Balance	97,328	$ 13,483
Original Issuer Premium (Discount)	0	0
Capitalized Fees & Expenses	(1,227)	(1,718)
Balance Sheet	96,101	11,765
Finance lease - real estate
Debt Instrument [Line Items]
Outstanding Balance	13,091	14,594
Original Issuer Premium (Discount)	0	0
Capitalized Fees & Expenses	0	(4)
Balance Sheet	13,091	14,590
Non U.S. lines of credit
Debt Instrument [Line Items]
Outstanding Balance	0	3,012
Original Issuer Premium (Discount)	0	0
Capitalized Fees & Expenses	(2)	(17)
Balance Sheet	(2)	2,995
Non U.S. term and mortgage loans
Debt Instrument [Line Items]
Outstanding Balance	12,090	25,684
Original Issuer Premium (Discount)	0	0
Capitalized Fees & Expenses	(27)	(91)
Balance Sheet	12,063	25,593
Other long term debt
Debt Instrument [Line Items]
Outstanding Balance	2,276	3,733
Original Issuer Premium (Discount)	0	0
Capitalized Fees & Expenses	(13)	(15)
Balance Sheet	$ 2,263	$ 3,718

Amount of long term capitalized fees and expenses.

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The current portion of long term debt gross value.

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The carrying amount of long-term debt, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities).

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, after accumulated amortization, of debt discount (premium).

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