New Accounting Pronouncements (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other pension and postretirement costs	$ 4	$ 3	$ 10	$ 10
Non-cash expense, pension and postretirement				6
Proceeds from deferred purchase price of factored receivables	$ 36	$ 28	102	$ 77
ASU 2016-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect on retained earnings, increase (decrease)			$ (2)