Other Expense (Income), Net - Schedule of Other Expenses (Income), Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Income and Expenses [Abstract]
Non-service related net periodic benefit cost	$ 112	$ 154	$ 135
Interest income	(23)	(19)	(16)
Foreign currency losses (gains), net	26	(5)	(4)
Net loss (gain) from asset sales	10	(513)	11
Other, net	(46)	(103)	(85)
Other income, net	$ 79	$ (486)	$ 41