Pension and Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Credit) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Pension Plan [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 13	$ 13	$ 26	$ 26
Expected return on plan assets	(21)	(23)	(42)	(46)
Service cost
Amortization of net actuarial loss	6	5	12	10
Net periodic benefit cost (credit)	(2)	(5)	(4)	(10)
Pension Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	2	2	4	4
Expected return on plan assets	(1)		(2)	(1)
Service cost	2	1	3	2
Other		1		1
Amortization of net actuarial loss	1	1	3	3
Net periodic benefit cost (credit)	4	5	8	9
Other Postretirement Benefits Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	1	1	2	2
Expected return on plan assets
Service cost
Amortization of net actuarial loss
Net periodic benefit cost (credit)	$ 1	$ 1	$ 2	$ 2