Inventories (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 2,990	$ 2,789
Work in process and other	2,805	2,506
Finished manufactured goods	4,338	4,033
Goods acquired for resale	6,798	6,399
Total inventory	$ 16,931	$ 15,727