XML 73 R58.htm IDEA: XBRL DOCUMENT v3.6.0.2
Inventories (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Inventory, Net [Abstract]    
Raw materials $ 59,415 $ 52,121
Work-in-process 35,539 34,025
Finished goods 26,613 15,988
Operating and other supplies 111,996 129,738
Inventories $ 233,563 $ 231,872