Property, Plant, and Equipment (Schedule of Property Plant and Equipment, Net) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Sep. 30, 2019
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 1,648,855	$ 1,672,227
Less accumulated depreciation	(615,277)	(613,452)
Property, plant, and equipment, net	1,033,578	1,058,775
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	89,483	94,976
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	575,988	587,541
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	17,810	17,446
Machinery and Production Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	733,995	731,159
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	123,187	124,201
Office furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	40,002	39,934
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	19,162	19,346
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 49,228	$ 57,624