Other (Income) Expense - Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Income and Expenses [Abstract]
(Gain) loss on sale and revaluation of assets	$ (43)	$ (80)	$ (130)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement, after tax	117
(Gain) Loss on Extinguishment of Debt	0	11	0
Other Nonoperating (Income) Expense	27	59	(19)
Other (income) expense - net	$ 101	$ (10)	$ (149)