Property, Plant, and Equipment (Schedule of Property Plant and Equipment, Net) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Sep. 30, 2018
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 1,670,309	$ 1,624,874
Less accumulated depreciation	(607,225)	(564,869)
Property, plant, and equipment, net	1,063,084	1,060,005
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	95,036	94,146
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	582,084	565,065
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	18,042	17,954
Machinery and Production Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	716,791	668,986
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	120,536	124,788
Office furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	36,916	31,533
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	19,337	19,366
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 81,567	$ 103,036