Pension and Postretirement Expense Level 4 (Details) - Change in Benefit Obligations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Foreign Plan [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	$ 548	$ 492
Service cost	16	14	$ 16
Interest cost	9	10	12
Actuarial losses (gains)	(6)	57
Foreign currency exchange rate changes	77	(13)
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(11)	(10)
Plan amendments	2	0
Expenses paid from assets	0	0
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant	1	1
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	1	1
Defined Benefit Plan, Other Cost (Credit)	0	0
Benefit obligation at end of year	636	548	492
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Actual return on plan assets	4	33
Foreign currency exchange rate changes	48	(10)
Employer contributions	21	19
Funded status of the plan at end of year	(224)	(199)
Defined Benefit Plan, Plan Assets, Benefits Paid	(11)	(10)
Defined Benefit Plan, Fair Value of Plan Assets	412	349	316
Foreign Plan [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	10	9
Service cost	0	0
Interest cost	1	1	1
Actuarial losses (gains)	0	(1)
Foreign currency exchange rate changes	0	1
Defined Benefit Plan, Benefit Obligation, Benefits Paid	0	0
Defined Benefit Plan, Benefit Obligation, Divestiture		0
Plan amendments	0	0
Expenses paid from assets	0	0
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant	0	0
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	0	0
Defined Benefit Plan, Other Cost (Credit)	0	0
Benefit obligation at end of year	11	10	9
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Actual return on plan assets	0	0
Foreign currency exchange rate changes	0	0
Employer contributions	0	0
Funded status of the plan at end of year	(11)	(10)
Defined Benefit Plan, Plan Assets, Benefits Paid	0	0
Defined Benefit Plan, Fair Value of Plan Assets	0	0	0
UNITED STATES | Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	242	249
Service cost	3	3	3
Interest cost	7	8	10
Actuarial losses (gains)	6	5
Foreign currency exchange rate changes	0	0
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(17)	(20)
Defined Benefit Plan, Benefit Obligation, Divestiture	0	0
Plan amendments	0	0
Expenses paid from assets	(3)	0
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant	0	0
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	0	0
Defined Benefit Plan, Other Cost (Credit)	0	(3)
Benefit obligation at end of year	238	242	249
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Actual return on plan assets	26	17
Foreign currency exchange rate changes	0	0
Employer contributions	0	3
Funded status of the plan at end of year	(25)	(35)
Defined Benefit Plan, Plan Assets, Benefits Paid	(17)	(20)
Defined Benefit Plan, Fair Value of Plan Assets	213	207	210
UNITED STATES | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	6	7
Service cost	0	0
Interest cost	0	0	0
Actuarial losses (gains)	(1)	0
Foreign currency exchange rate changes	0	0
Defined Benefit Plan, Benefit Obligation, Benefits Paid	0	1
Defined Benefit Plan, Benefit Obligation, Divestiture	0	0
Plan amendments	0	0
Expenses paid from assets	0	0
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant	0	0
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	0	0
Defined Benefit Plan, Other Cost (Credit)	0	0
Benefit obligation at end of year	5	6	7
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Actual return on plan assets	0	0
Foreign currency exchange rate changes	0	0
Employer contributions	1	1
Funded status of the plan at end of year	(5)	(6)
Defined Benefit Plan, Plan Assets, Benefits Paid	(1)	(1)
Defined Benefit Plan, Fair Value of Plan Assets	0	0	$ 0
Non-US [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Divestiture	0	$ (3)
Non-US [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Divestiture	$ 0