Summary of Accounting Policies - Plant, Property, and Equipment, at Cost (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Plant, property, and equipment, at cost	$ 3,548	$ 3,418
Land, buildings, and improvements
Property, Plant and Equipment [Line Items]
Plant, property, and equipment, at cost	$ 568	561
Buildings and improvements | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life of plant, property and equipment	10 years
Buildings and improvements | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life of plant, property and equipment	50 years
Machinery and equipment
Property, Plant and Equipment [Line Items]
Plant, property, and equipment, at cost	$ 2,638	2,569
Machinery and equipment | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life of plant, property and equipment	3 years
Machinery and equipment | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life of plant, property and equipment	25 years
Other, including construction in progress
Property, Plant and Equipment [Line Items]
Plant, property, and equipment, at cost	$ 342	$ 288