Annual report pursuant to Section 13 and 15(d)

Other Assets - Other Noncurrent Assets (Details)

v3.7.0.1
Other Assets - Other Noncurrent Assets (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Summary of other noncurrent assets    
Spare parts inventory $ 3,532 $ 2,922
Catalysts 4,479 5,742
Deposits 2,392 2,370
Other 2,227 785
Total $ 12,630 $ 11,819