Supplemental Balance Sheet Information - Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Land and mineral deposits	$ 131	$ 135
Buildings and improvements	1,088	1,095
Machinery and equipment	2,505	2,563
Property, plant and equipment, gross	3,724	3,793
Reserves for depreciation and depletion	(1,936)	(1,885)
Total	1,788	1,908
Annual depreciation and depletion expense	$ 130	$ 134