|3 Months Ended|
Mar. 31, 2019
|Inventory Disclosure [Abstract]|
Inventories consisted of the following (in thousands of dollars):
The entire disclosure for inventory. Includes, but is not limited to, the basis of stating inventory, the method of determining inventory cost, the classes of inventory, and the nature of the cost elements included in inventory.
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef