Repositioning Charges - Summary of Pretax Distribution of Total Net Repositioning Charges by Statement of Operations Classification (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost And Reserve [Line Items]
Total net repositioning charges	$ 5	$ 23	$ 19
Cost of Goods Sold
Restructuring Cost And Reserve [Line Items]
Total net repositioning charges	4	17	0
Selling, General and Administrative Expenses
Restructuring Cost And Reserve [Line Items]
Total net repositioning charges	$ 1	$ 6	$ 19