Other (Income) Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Gain (Loss) on Sale and Revaluation of Assets	$ 33	$ 15	$ 45	$ 66
Other (income) expense - net	8	0	3	62
Other (Income) Expense - Net	(25)	(4)	(42)	7
Gain (Loss) on Extinguishment of Debt	0	$ 11	0	11
Other (Income) Expense - Net [Member]
Defined benefit plan net periodic benefit cost other than service cost	$ 1		$ (4)	$ (20)