LONG-TERM DEBT - Summary of Interest Expense Incurred (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Debt Instrument [Line Items]
Cash Interest, Capitalized Interest	$ (76)	$ 0	$ (230)	$ (13)
Cash Interest	22,835	15,214	58,358	45,386
Amort. Debt (Premium)/Discount	49	(12)	55	(35)
Amort. Debt Issuance Costs & Other Fees	1,138	647	2,698	2,019
Total Interest Expense	$ 24,022	$ 15,849	$ 61,111	$ 47,370
Senior notes due 2028
Debt Instrument [Line Items]
Effective Interest Rate	6.00%	6.00%	6.00%	6.00%
Cash Interest, Including Amounts Capitalized	$ 14,340	$ 14,375	$ 43,090	$ 43,125
Amort. Debt (Premium)/Discount	(12)	(12)	(36)	(35)
Amort. Debt Issuance Costs & Other Fees	516	496	1,552	1,566
Total Interest Expense	$ 14,844	14,859	$ 44,606	44,656
Term Loan B due 2029
Debt Instrument [Line Items]
Effective Interest Rate	3.90%		3.70%
Cash Interest, Including Amounts Capitalized	$ 7,129	0	$ 11,896	0
Amort. Debt (Premium)/Discount	61	0	91	0
Amort. Debt Issuance Costs & Other Fees	485	0	717	0
Total Interest Expense	7,675	0	12,704	0
Revolver due 2025
Debt Instrument [Line Items]
Cash Interest, Including Amounts Capitalized	1,056	344	2,307	760
Amort. Debt (Premium)/Discount	0	0	0	0
Amort. Debt Issuance Costs & Other Fees	123	123	368	368
Total Interest Expense	$ 1,179	$ 467	$ 2,675	$ 1,128
Finance lease - real estate
Debt Instrument [Line Items]
Effective Interest Rate	5.60%	5.70%	5.60%	5.40%
Cash Interest, Including Amounts Capitalized	$ 187	$ 215	$ 577	$ 671
Amort. Debt (Premium)/Discount	0	0	0	0
Amort. Debt Issuance Costs & Other Fees	0	6	4	19
Total Interest Expense	187	221	581	690
Non US lines of credit
Debt Instrument [Line Items]
Cash Interest, Including Amounts Capitalized	4	4	14	11
Amort. Debt (Premium)/Discount	0	0	0	0
Amort. Debt Issuance Costs & Other Fees	5	4	12	12
Total Interest Expense	9	8	26	23
Non US term loans
Debt Instrument [Line Items]
Cash Interest, Including Amounts Capitalized	141	169	492	503
Amort. Debt (Premium)/Discount	0	0	0	0
Amort. Debt Issuance Costs & Other Fees	9	18	44	53
Total Interest Expense	150	187	536	556
Other long term debt
Debt Instrument [Line Items]
Cash Interest, Including Amounts Capitalized	54	107	212	329
Amort. Debt (Premium)/Discount	0	0	0	0
Amort. Debt Issuance Costs & Other Fees	0	0	1	1
Total Interest Expense	$ 54	$ 107	$ 213	$ 330

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

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