Pension and Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Credit) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 17	$ 20	$ 34	$ 40
Expected return on plan assets	$ (28)	$ (28)	$ (55)	$ (55)
Service cost
Amortization of net actuarial loss	$ 5	$ 4	$ 10	$ 8
Net periodic benefit cost (credit)	(6)	(4)	(11)	(7)
Foreign Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 2	$ 3	4	$ 6
Expected return on plan assets			(1)
Service cost	$ 1	$ 2	3	$ 3
Amortization of net actuarial loss	2	1	3	2
Net periodic benefit cost (credit)	5	6	9	11
Foreign Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 1	$ 2	$ 2	$ 3
Expected return on plan assets
Service cost
Amortization of net actuarial loss
Net periodic benefit cost (credit)	$ 1	$ 2	$ 2	$ 3