Pension and Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Credit) and Other Amounts Recognized in OCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Plan [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 51	$ 53	$ 66
Expected return on plan assets	(82)	(92)	(108)
Service cost
Amortization of net actuarial (gain) loss	23	21	18
Other
Net periodic benefit cost (credit)	(8)	(18)	(24)
Recognized in OCI:
Amount due to net actuarial (gains) losses	22	68	40
Reclassification adjustment for net actuarial gains (losses) in net periodic benefit cost	(23)	(21)	(18)
Other
Total recognized in OCI	(1)	47	22
Net recognized in benefit cost (credit) and OCI	(9)	29	(2)
Pension Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	7	7	8
Expected return on plan assets	(3)	(2)	(2)
Service cost	7	5	5
Amortization of net actuarial (gain) loss	7	6	7
Termination benefit	1
Other		1
Net periodic benefit cost (credit)	19	17	18
Recognized in OCI:
Amount due to net actuarial (gains) losses	4	16	(6)
Reclassification adjustment for net actuarial gains (losses) in net periodic benefit cost	(7)	(6)	(7)
Curtailment	(1)
Other		(1)	(11)
Total recognized in OCI	(4)	9	(24)
Net recognized in benefit cost (credit) and OCI	15	26	(6)
Other Postretirement Benefits Plan [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	3	3	3
Service cost	1	1	1
Amortization of net actuarial (gain) loss		(1)
Net periodic benefit cost (credit)	4	3	4
Recognized in OCI:
Amount due to net actuarial (gains) losses	2	4	(6)
Reclassification adjustment for net actuarial gains (losses) in net periodic benefit cost		1
Total recognized in OCI	2	5	(6)
Net recognized in benefit cost (credit) and OCI	$ 6	$ 8	$ (2)