LONG-TERM DEBT - Summary of Interest Expense Incurred (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Debt Instrument [Line Items]
Cash Interest, Capitalized Interest	$ (9)	$ (81)	$ (11)	$ (154)
Cash Interest	23,856	20,496	47,481	35,523
Amort. Debt (Premium)/Discount	31	18	62	6
Amort. Debt Issuance Costs & Other Fees	992	894	1,984	1,560
Total Interest Expense	$ 24,879	$ 21,408	$ 49,527	$ 37,089
Senior notes due 2028
Debt Instrument [Line Items]
Effective Interest Rate	6.00%	5.90%	6.00%	6.00%
Cash Interest, Including Amounts Capitalized	$ 14,012	$ 14,375	$ 28,024	$ 28,750
Amort. Debt (Premium)/Discount	(12)	(12)	(24)	(24)
Amort. Debt Issuance Costs & Other Fees	505	518	1,010	1,036
Total Interest Expense	$ 14,505	$ 14,881	$ 29,010	$ 29,762
Term Loan B due 2029
Debt Instrument [Line Items]
Effective Interest Rate	7.50%	3.40%	7.00%	3.40%
Cash Interest, Including Amounts Capitalized	$ 8,737	$ 4,767	$ 16,545	$ 4,767
Amort. Debt (Premium)/Discount	43	30	86	30
Amort. Debt Issuance Costs & Other Fees	352	232	703	232
Total Interest Expense	9,132	5,029	17,334	5,029
Revolver due 2025
Debt Instrument [Line Items]
Cash Interest, Including Amounts Capitalized	673	990	2,017	1,251
Amort. Debt (Premium)/Discount	0	0	0	0
Amort. Debt Issuance Costs & Other Fees	122	123	245	245
Total Interest Expense	$ 795	$ 1,113	$ 2,262	$ 1,496
Finance lease - real estate
Debt Instrument [Line Items]
Effective Interest Rate	5.60%	5.60%	5.60%	5.60%
Cash Interest, Including Amounts Capitalized	$ 174	$ 192	$ 352	$ 390
Amort. Debt (Premium)/Discount	0	0	0	0
Amort. Debt Issuance Costs & Other Fees	0	0	0	4
Total Interest Expense	174	192	352	394
Non US lines of credit
Debt Instrument [Line Items]
Cash Interest, Including Amounts Capitalized	205	7	360	10
Amort. Debt (Premium)/Discount	0	0	0	0
Amort. Debt Issuance Costs & Other Fees	12	3	25	7
Total Interest Expense	217	10	385	17
Non US term loans
Debt Instrument [Line Items]
Cash Interest, Including Amounts Capitalized	0	185	0	351
Amort. Debt (Premium)/Discount	0	0	0	0
Amort. Debt Issuance Costs & Other Fees	0	18	0	35
Total Interest Expense	0	203	0	386
Other long term debt
Debt Instrument [Line Items]
Cash Interest, Including Amounts Capitalized	64	61	194	158
Amort. Debt (Premium)/Discount	0	0	0	0
Amort. Debt Issuance Costs & Other Fees	1	0	1	1
Total Interest Expense	$ 65	$ 61	$ 195	$ 159

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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