Property, Plant and Equipment - Components of Property, Plant and Equipment (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 9,374	$ 8,638
Accumulated depreciation	(5,745)	(5,160)
Property, plant and equipment, net	3,629	3,478
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	246	229
Equipment and software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	6,557	5,973
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,291	2,089
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	160	132
Building construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	120	215
Facilities not yet placed in service, holding for future use
Property, Plant and Equipment [Line Items]
Building construction in progress	$ 74