Annual report pursuant to Section 13 and 15(d)

Reportable Segments - Capital Expenditures (Details)

v3.8.0.1
Reportable Segments - Capital Expenditures (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets      
Capital expenditures gross $ 141,083 $ 130,312 $ 41,854
Capital expenditure 140,482 121,421 40,994
Change in non-cash capital expenditures in accounts payable (601) (8,891) (860)
Operating segments | Performance Materials & Chemicals      
Revenues from External Customers and Long-Lived Assets      
Capital expenditures gross 87,938 74,392 0
Operating segments | Environmental Catalysts & Services      
Revenues from External Customers and Long-Lived Assets      
Capital expenditures gross 66,511 74,921 41,854
Operating segments | Environmental Catalysts & Services | Zeolyst Joint Venture      
Revenues from External Customers and Long-Lived Assets      
Capital expenditure 13,366 19,001  
Eliminations      
Revenues from External Customers and Long-Lived Assets      
Capital expenditures gross $ (13,366) $ (19,001) $ 0