Inventories (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Inventory, Net [Abstract]
Raw materials and supplies	$ 21,501	$ 21,476
Work in progress	18,241	19,400
Finished goods	114,834	116,079
Total inventories	$ 154,576	$ 156,955