Property, Plant, and Equipment (Schedule of Property Plant and Equipment, Net) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Sep. 30, 2019
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 1,651,495	$ 1,672,227
Less accumulated depreciation	(632,417)	(613,452)
Property, plant, and equipment, net	1,019,078	1,058,775
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	89,142	94,976
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	576,123	587,541
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	17,957	17,446
Machinery and Production Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	746,128	731,159
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	122,488	124,201
Office furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	39,734	39,934
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	19,767	19,346
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 40,156	$ 57,624