Inventories (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Inventory Disclosure [Abstract]
Raw materials	$ 2,909	$ 1,852
Work in process and other	2,461	778
Finished manufactured goods	4,287	3,369
Goods acquired for resale	6,106	5,917
Total inventory	$ 15,763	$ 11,916