Inventories (Tables)

9 Months Ended

Sep. 30, 2018

Inventory Disclosure [Abstract]

Inventories

Inventories (principally using the last-in, first-out (LIFO) method) are comprised of the following:

(Millions of dollars)	September 30, 2018		December 31, 2017
Raw materials	$	3,413	$	2,802
Work-in-process	2,764		2,254
Finished goods	5,425		4,761
Supplies	212		201
Total inventories	$	11,814	$	10,018