Inventories (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Inventory Disclosure [Abstract]
Raw materials	$ 2,851	$ 1,852
Work in process and other	2,519	778
Finished manufactured goods	4,461	3,369
Goods acquired for resale	6,006	5,917
Total inventory	$ 15,837	$ 11,916