Business Segments - Geographic Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales	$ 15,377	$ 15,158	$ 16,443
Long-Lived Assets	7,451	7,040	6,777
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales	6,678	6,724	7,338
Long-Lived Assets	2,750	2,651	2,468
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	766	716	766
Germany
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales	1,874	1,853	1,905
Long-Lived Assets	727	717	778
Other international
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales	6,825	6,581	7,200
Long-Lived Assets	$ 3,208	$ 2,956	$ 2,765