Other (Income) Expense - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Other (Income) Expense [Line Items]
Other (Income) Expense	$ 22	$ 37
Accounting Standards Update, Pension and Postretirement Benefits Cost | Restatement Adjustment
Other (Income) Expense [Line Items]
Other (Income) Expense		$ 9