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Inventories (Policies)
12 Months Ended
Dec. 31, 2018
Inventory Disclosure [Abstract]  
Inventory
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.