Inventories (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Inventory Disclosure [Abstract]
Raw materials	$ 55,369	$ 60,157
Finished goods	95,071	108,334
Spare parts	13,858	12,976
Inventory, Net	164,298	181,467
Inventory Valuation Reserves	$ 12,372	$ 13,857