Inventories Breakdown of Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Finished goods	$ 414,607	$ 262,769
Raw materials	113,687	53,152
Work in process	45,140	0
Stores, supplies and other	55,959	42,440
Total inventories	$ 629,393	$ 358,361