Inventories (Policies)

12 Months Ended

Dec. 31, 2017

Inventory Disclosure [Abstract]

Inventory

We state all inventories at the lower of cost or market. We use the last-in, first-out (LIFO) method for the majority of our inventories located in the continental U.S. Other inventories are valued by the first-in, first-out (FIFO) method. FIFO cost approximates current replacement cost.