Inventories (Tables)

9 Months Ended

Sep. 30, 2015

Inventory Disclosure [Abstract]

Inventories

Inventories are valued at the lower of cost or market, principally using the last-in, first-out (LIFO) method, and are comprised of the following:

(Millions of dollars)	September 30, 2015		December 31, 2014
Raw materials	$	2,862	$	2,986
Work-in-process	1,987		2,455
Finished goods	6,042		6,504
Supplies	259		260
Total inventories	$	11,150	$	12,205