Quarterly report pursuant to Section 13 or 15(d)

Inventories (Details)

v3.8.0.1
Inventories (Details) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Inventory, Net    
Finished products and work in process $ 223,019 $ 199,919
Raw materials 60,771 62,469
Inventory, Net 283,790 262,388
Valued at lower of cost or market:    
LIFO basis 177,632 162,315
FIFO or average cost basis 106,158 100,073
Inventory, Net $ 283,790 $ 262,388