Property, Plant, and Equipment (Schedule of Property Plant and Equipment, Net) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 1,657,028	$ 1,651,390
Less accumulated depreciation	(691,823)	(653,975)
Property, plant, and equipment, net	965,205	997,415
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	86,131	83,095
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	551,726	551,540
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	19,164	18,610
Machinery and Production Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	788,147	776,884
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	123,001	123,903
Office Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	41,249	41,177
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	19,838	19,814
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 27,772	$ 36,367