Inventories (Tables)

12 Months Ended

Dec. 31, 2018

Inventory Disclosure [Abstract]

Schedule of inventories

Inventories are comprised of the following (in millions).

	December 31,
	2018		2017
Raw materials	$	4,182	$	3,479
Work in process and other		2,625		2,568
Finished manufactured goods		4,541		4,505
Goods acquired for resale		7,721		6,814
	$	19,069	$	17,366