Property, Plant, and Equipment, Net (Property, Plant, and Equipment - Net) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Sep. 30, 2015
Property, Plant, and Equipment, Net
Land and Land Improvements	$ 87,466		$ 87,466		$ 79,311
Buildings and improvements	523,238		523,238		372,160
Leasehold improvements	14,018		14,018		16,907
Machinery and production equipment	417,435		417,435		365,040
Computer equipment and software	112,273		112,273		118,154
Office furniture and equipment	25,517		25,517		20,939
Other	18,371		18,371		18,325
Construction in progress	138,798		138,798		252,763
Property, Plant and Equipment, Gross, Total	1,337,116		1,337,116		1,243,599
Less accumulated depreciation	(492,661)		(492,661)		(487,499)
Property, Plant and Equipment, Net, Total	844,455		844,455		$ 756,100
Depreciation expense	10,413	$ 11,280	29,162	$ 33,727
Capitalized interest	$ 914	$ 2,544	$ 5,054	$ 7,310