Property, Plant and Equipment - Components of Property, Plant and Equipment (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 10,180	$ 9,543
Accumulated depreciation	(6,389)	(5,777)
Property, plant and equipment, net	3,791	3,766
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	280	255
Equipment and software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	7,305	6,684
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,357	2,308
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	170	162
Building construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	68	$ 134
Facilities not yet placed in service, holding for future use
Property, Plant and Equipment [Line Items]
Building construction in progress	$ 39