Pension and Other Postretirement Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		75 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2	$ 2	$ 4	$ 4
Interest cost	4	4	8	8
Expected return on plan assets	0	0	0	0
Amortization:
Actuarial loss	0	0	0	0
Prior service credit	(3)	(4)	(7)	(8)
Settlement and curtailment (gain) loss	0	0	0	0
Net periodic cost	3	2	5	4	$ (103)
United States Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	1	1
Interest cost	33	37	67	74
Expected return on plan assets	(44)	(46)	(88)	(93)
Amortization:
Actuarial loss	13	11	25	23
Prior service credit	0	(1)	(1)	(2)
Settlement and curtailment (gain) loss	0	0	0	0
Net periodic cost	2	1	4	3
Foreign Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2	3	3
Interest cost	6	7	11	14
Expected return on plan assets	(8)	(8)	(15)	(16)
Amortization:
Actuarial loss	1	1	3	2
Prior service credit	0	0	0	0
Settlement and curtailment (gain) loss	1	(1)	1	0
Net periodic cost	$ 2	$ 1	$ 3	$ 3