Other (Income) Expense - Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Income and Expenses [Abstract]
(Gain) loss on sale and revaluation of assets	$ (80)	$ (130)	$ (572)
(Gain) Loss on Extinguishment of Debt	11	0	189
Other Nonoperating (Income) Expense	32	(17)	33
Other (income) expense - net	$ (37)	$ (147)	$ (350)