Pension and Postretirement Expense Level 4 (Details) - Components of net pension and postretirement expense benefit - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Pension Plan [Member] | UNITED STATES
Pension Benefits and Non-Pension Postretirement Benefits Disclosures Table Text Block [Line Items]
Service cost	$ 1	$ 1
Interest cost on projected benefit obligation	2	2
Expected return on assets	(4)	(4)
Net expense (benefit)	(1)	(1)
Pension Plan [Member] | Foreign Plan [Member]
Pension Benefits and Non-Pension Postretirement Benefits Disclosures Table Text Block [Line Items]
Service cost	4	4
Interest cost on projected benefit obligation	3	2
Expected return on assets	(3)	(2)
Net expense (benefit)	4	4
Other Postretirement Benefits Plan [Member] | UNITED STATES
Pension Benefits and Non-Pension Postretirement Benefits Disclosures Table Text Block [Line Items]
Service cost	0	0
Interest cost on projected benefit obligation	0	0
Expected return on assets	0	0
Net expense (benefit)	0	0
Other Postretirement Benefits Plan [Member] | Foreign Plan [Member]
Pension Benefits and Non-Pension Postretirement Benefits Disclosures Table Text Block [Line Items]
Service cost	0	0
Interest cost on projected benefit obligation	0	0
Expected return on assets	0	0
Net expense (benefit)	$ 0	$ 0