Property, Plant and Equipment - Components of Property, Plant and Equipment (Detail) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 10,401	$ 10,288
Accumulated depreciation	(6,676)	(6,438)
Property, plant and equipment, net	3,725	3,850
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	283	283
Equipment and software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	7,439	7,378
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,401	2,373
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	172	171
Building construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	106	$ 83
Facilities not yet placed in service, holding for future use
Property, Plant and Equipment [Line Items]
Building construction in progress	$ 66