Pension Benefits Benefit Obligations and Fair Value of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations [Abstract]
Fair Value of Plan Assets	$ 377	$ 1,212
Liability, Other Retirement Benefits	4	5
U.S. Plans
Defined Benefit Plan, Pension Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Defined Benefit Plan, PBO	29	40
Defined Benefit Plan, ABO	29	40
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations [Abstract]
Defined Benefit Plan, PBO	0	0
Defined Benefit Plan, ABO	0	0
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Defined Benefit Plan, Benefit Obligation	29	40	$ 50
Defined Benefit Plan, Accumulated Benefit Obligation	29	40
Fair Value of Plan Assets	0	0	0
Non-U.S. Plans
Defined Benefit Plan, Pension Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Defined Benefit Plan, PBO	743	2,030
Defined Benefit Plan, ABO	701	1,805
Defined Benefit Plan, Fair Value of Plan Assets	282	1,100
Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations [Abstract]
Defined Benefit Plan, PBO	92	107
Defined Benefit Plan, ABO	64	74
Defined Benefit Plan, Fair Value of Plan Assets	95	112
Defined Benefit Plan, Benefit Obligation	835	2,137	2,032
Defined Benefit Plan, Accumulated Benefit Obligation	765	1,879
Fair Value of Plan Assets	$ 377	$ 1,212	$ 1,209