Restructuring and Related Implementation Charges - Summary of Restructuring and Related Costs (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax									$ 169	$ 105	$ 170
Global Growth and Efficiency Program
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax									333	228	254
Total Global Growth and Efficiency Program charges, aftertax	$ 61	$ 39	$ 115	$ 31	$ 54	$ 32	$ 44	$ 38	246	168	183
Global Growth and Efficiency Program | Cost of sales
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax	$ 24	$ 16	$ 21	$ 14	$ 15	$ 11	$ 12	$ 8	75	46	20
Global Growth and Efficiency Program | Selling, general and administrative expenses
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax									89	77	64
Global Growth and Efficiency Program | Other (income) expense, net
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax									$ 169	$ 105	$ 170