Asset Impairment, Exit and Implementation Costs (Facilities Consolidation) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 15	$ 6	$ 71	$ 130
Payments for restructuring			54
Facilities Consolidation [Member]
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	$ 150		$ 150		$ 150
Expected restructuring charges, per share (usd per share)	$ 0.05		$ 0.05		$ 0.05
Restructuring charges	$ 15		$ 71		$ 142	$ 71
Charges (in usd per share)						$ 0.03
Charges expected to result in cash expenditures	90
Payments for restructuring			46		51
Facilities Consolidation [Member] | Accelerated Depreciation and Asset Impairment [Member]
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	55		55		55
Facilities Consolidation [Member] | Employee Separation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	45		45		45
Facilities Consolidation [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	$ 50		$ 50		$ 50