PROPERTY, PLANT AND EQUIPMENT - Summary of Property Plant and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Sep. 30, 2019
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	$ 796,261
Property plant and equipment gross		$ 763,542
Accumulated depreciation and amortization	(460,943)
Accumulated depreciation and amortization		(426,216)
Total	335,318
Total		337,326
Land, building and building improvements
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	159,225
Property plant and equipment gross		133,036
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	585,298
Property plant and equipment gross		580,698
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	$ 51,738
Property plant and equipment gross		$ 49,808

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount of accumulated depreciation and amortization from plant, property, and equipment and right-of-use asset from finance lease.

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Amount, before accumulated depreciation and amortization, of property, plant, and equipment and finance lease right-of-use asset.

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