Asset Impairment, Exit, and Restructuring Costs (Asset Impairment Charges And Exit Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring, Settlement and Impairment Provisions [Abstract]
Relocation and restructuring costs	$ 72	$ 21	$ 71
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	0	6	0
Goodwill and Intangible Asset Impairment	0	11	21
Other Asset Impairment Charges	101	17	108
Restructuring, Settlement and Impairment Provisions	$ 173	$ 55	$ 200