Accumulated Other Comprehensive Loss (Details 2) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Reclassifications out of accumulated other comprehensive income loss by component
Other (expense) income, net	$ (7)	$ 10	$ (13)	$ 33
Net actuarial loss | Amount reclassified from accumulated other comprehensive loss
Reclassifications out of accumulated other comprehensive income loss by component
Other (expense) income, net	52	45	103	87
Prior service cost | Amount reclassified from accumulated other comprehensive loss
Reclassifications out of accumulated other comprehensive income loss by component
Other (expense) income, net	3	3	6	6
Defined benefit plan
Reclassifications out of accumulated other comprehensive income loss by component
Total before tax	55	48	109	93
Income tax benefit	(23)	(18)	(44)	(35)
Net of tax	$ 32	$ 30	$ 65	$ 58