Repositioning Charges - Summary of Pretax Distribution of Total Net Repositioning Charges by Statement of Operations Classification (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring Cost And Reserve [Line Items]
Total net repositioning charges	$ 0	$ 5	$ 2	$ 5	$ 21
Cost of Goods Sold
Restructuring Cost And Reserve [Line Items]
Total net repositioning charges	0		2	4	16
Selling, General and Administrative Expenses
Restructuring Cost And Reserve [Line Items]
Total net repositioning charges	$ 0		$ 0	$ 1	$ 5