Restructuring and Related Implementation Charges - Summary of Restructuring and Related Costs (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax									$ 88	$ 152	$ 93
Global Growth and Efficiency Program
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax									161	333	228
Total Global Growth and Efficiency Program charges, aftertax	$ 32	$ 22	$ 51	$ 20	$ 61	$ 39	$ 115	$ 31	125	246	168
Global Growth and Efficiency Program | Cost of sales
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax	$ 12	$ 8	$ 5	$ 6	$ 24	$ 16	$ 21	$ 14	31	75	46
Global Growth and Efficiency Program | Selling, general and administrative expenses
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax									33	86	77
Global Growth and Efficiency Program | Other (income) expense, net
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax									88	152	93
Global Growth and Efficiency Program | Non-service related postretirement costs
Restructuring Cost and Reserve [Line Items]
Total Global Growth and Efficiency Program charges, pretax									$ 9	$ 20	$ 12