Inventories (Detail) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Raw materials	$ 1,855	$ 1,881
Work in process and other	855	850
Finished manufactured goods	3,516	3,333
Goods acquired for resale	5,846	4,172
Total inventory	$ 12,072	$ 10,236