XML 76 R57.htm IDEA: XBRL DOCUMENT v3.8.0.1
Property, plant and equipment (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Property, Plant and Equipment [Abstract]    
Land and improvements $ 41,823 $ 42,654
Buildings and improvements 331,735 330,254
Machinery and equipment 1,398,687 1,374,551
Construction in progress 22,517 21,106
Property, plant and equipment, gross 1,794,762 1,768,565
Less accumulated depreciation (822,846) (742,280)
Property, plant and equipment - net $ 971,916 $ 1,026,285