NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Dec. 18, 2017
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	$ 62,673	$ 60,349	$ 47,002
Amortization of Debt Discount (Premium)	270	270	1,518
Amortization of Debt Issuance Costs	5,123	4,949	2,993
Interest Expense, Debt	68,066	65,568	51,513
Capitalized interest	(385)	$ (549)	(795)
Effective Interest Rate		5.66%
Outstanding Balance	1,114,131	$ 1,134,692
less: Current portion	(10,525)	(13,011)
Long-term debt	1,103,606	1,121,681
Original Issuer Discount	867	1,220
less: Current portion	0	0
Capitalized Fees & Expenses, Current	0	0
Long-term debt	(867)	(1,220)
Capitalized Fees & Expenses, Noncurrent	(10,724)	(14,830)
Balance Sheet	1,104,274	1,121,082
less: Current portion	(10,525)	(13,011)
Long-term debt	1,093,749	1,108,071
Capitalized fees & expenses	(10,724)	(14,830)
Senior note due 2022 [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	52,500	52,500	38,063
Amortization of Debt Discount (Premium)	270	270	270
Amortization of Debt Issuance Costs	3,803	3,803	1,857
Interest Expense, Debt	$ 56,573	56,573	$ 40,190
Effective Interest Rate	5.66%		5.55%
Outstanding Balance	$ 1,000,000
Original Issuer Discount	867
Balance Sheet	991,692
Capitalized fees & expenses	$ (9,175)			$ (8,472)
Coupon Interest Rate	5.25%
Revolving Credit Facility [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities		3,718
Amortization of Debt Discount (Premium)		0
Amortization of Debt Issuance Costs		565
Interest Expense, Debt		4,283
Senior notes due 2018 [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Outstanding Balance		1,000,000
Original Issuer Discount		1,220
Balance Sheet		988,252
Capitalized fees & expenses		$ (12,968)
Coupon Interest Rate		5.25%
Revolver due 2019 [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Outstanding Balance	$ 50,000	$ 25,000
Original Issuer Discount	0	0
Balance Sheet	48,757	23,587
Capitalized fees & expenses	(1,243)	(1,413)
Convert. debt due 2017 [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities			$ 1,167
Amortization of Debt Discount (Premium)			1,248
Amortization of Debt Issuance Costs			148
Interest Expense, Debt			$ 2,563
Effective Interest Rate			8.90%
Real estate mortgages [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities		349	$ 582
Amortization of Debt Discount (Premium)		0	0
Amortization of Debt Issuance Costs		320	58
Interest Expense, Debt		$ 669	$ 640
Effective Interest Rate		3.30%	2.60%
ESOP Loans [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	937	$ 1,802	$ 1,557
Amortization of Debt Discount (Premium)	0	0	0
Amortization of Debt Issuance Costs	186	124	133
Interest Expense, Debt	$ 1,123	$ 1,926	$ 1,690
Effective Interest Rate	6.30%	6.30%	4.20%
Outstanding Balance		$ 34,694
Original Issuer Discount		0
Balance Sheet		34,508
Capitalized fees & expenses		(186)
Capital lease - real estate [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	$ 372	581	$ 296
Amortization of Debt Discount (Premium)	0	0	0
Amortization of Debt Issuance Costs	25	25	25
Interest Expense, Debt	397	606	$ 321
Effective Interest Rate			5.50%
Outstanding Balance	4,388	7,503
Original Issuer Discount	0	0
Balance Sheet	4,333	7,423
Capitalized fees & expenses	$ (55)	$ (80)
Coupon Interest Rate	5.00%	5.00%
Non U.S. lines of credit [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	$ 19	$ 34	$ 76
Amortization of Debt Discount (Premium)	0	0	0
Amortization of Debt Issuance Costs	15	15	128
Interest Expense, Debt	34	49	204
Outstanding Balance	17,576	7,951
Original Issuer Discount	0	0
Balance Sheet	17,531	7,935
Capitalized fees & expenses	(45)	(16)
Non U.S. term loans [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	1,592	1,420	860
Amortization of Debt Discount (Premium)	0	0	0
Amortization of Debt Issuance Costs	109	90	67
Interest Expense, Debt	1,701	1,510	927
Outstanding Balance	36,977	53,533
Original Issuer Discount	0	0
Balance Sheet	36,789	53,385
Capitalized fees & expenses	(188)	(148)
Other long term debt [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	640	494	245
Amortization of Debt Discount (Premium)		0	0
Amortization of Debt Issuance Costs	5	7	10
Interest Expense, Debt	645	501	$ 255
Outstanding Balance	5,190	6,011
Original Issuer Discount	0	0
Balance Sheet	5,172	5,992
Capitalized fees & expenses	$ (18)	$ (19)