Property, Plant, and Equipment, Net (Property, Plant, and Equipment - Net) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 1,467,154		$ 1,442,896
Less accumulated depreciation	(536,996)		(520,853)
Property, Plant and Equipment, Net, Total	930,158		922,043
Depreciation expense	14,827	$ 12,455
Capitalized interest	601	$ 472
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	88,536		88,326
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	515,338		514,453
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	16,425		16,142
Machinery and Equipment, Excluding Computer and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	560,264		543,641
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	125,628		124,723
Office furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	24,455		24,308
Other Capitalized Property Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	19,423		19,393
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 117,085		$ 111,910