Benefit Obligations (Schedule of Principle Weighted Average Assumptions Used to Determine Benefit Obligations and Benefit Cost) (Details)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate obligations		3.30%	3.70%
Rate of compensation increase		2.80%	2.80%
Discount rate NPBC		3.70%	4.00%	3.70%
Discount rate NPBC - service cost	[1]	2.50%	3.10%	3.70%
Discount rate NPBC - interest cost	[1]	3.10%	3.20%	3.70%
Expected return on plan assets		7.30%	7.30%	7.80%
Rate of compensation increase NPBC		2.80%	2.70%	2.80%
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate obligations		3.20%	3.40%
Discount rate NPBC		3.40%	3.90%	3.60%
Discount rate NPBC - service cost	[1]	2.90%	3.80%	3.60%
Discount rate NPBC - interest cost	[1]	2.90%	3.10%	3.60%
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase		2.80%	2.80%
Expected return on plan assets		5.90%	6.10%	6.00%
Rate of compensation increase NPBC		2.80%	2.70%	2.80%
Foreign Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate obligations		2.10%	2.10%
Discount rate NPBC		2.10%	2.60%	2.40%
Discount rate NPBC - service cost	[1]	2.50%	3.10%	2.40%
Discount rate NPBC - interest cost	[1]	1.70%	2.20%	2.40%
Foreign Plan [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate obligations		3.20%	3.30%
Discount rate NPBC		3.30%	3.60%	3.50%
Discount rate NPBC - service cost	[1]	3.40%	3.80%	3.50%
Discount rate NPBC - interest cost	[1]	2.90%	3.10%	3.50%
Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets		7.50%	7.50%	8.00%
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate obligations		3.50%	3.90%
Discount rate NPBC		3.90%	4.20%	3.90%
Discount rate NPBC - service cost	[1]	1.20%	4.50%	3.90%
Discount rate NPBC - interest cost	[1]	3.30%	3.40%	3.90%
Domestic Plan [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate obligations		3.40%	3.80%
Discount rate NPBC		3.80%	4.00%	3.70%
Discount rate NPBC - service cost	[1]	4.00%	4.20%	3.70%
Discount rate NPBC - interest cost	[1]	3.10%	3.10%	3.70%

[1] eighted-average discount rates reflect the adoption of the full yield curve approach.