Employee Benefit Plans (Weighted-average Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits [Member]
Weighted-average assumptions used to determine benefit obligations as of December 31:
Discount rate	3.66%	4.17%
Rate of compensation increase	4.23%	4.23%
Weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31:
Discount rate - service cost	3.96%	4.30%	3.97%
Discount rate - interest cost	3.51%	3.76%	3.97%
Expected long-term return on plan assets	7.50%	7.50%	7.50%
Rate of compensation increase	4.23%	4.23%	4.23%
Other Benefits [Member]
Weighted-average assumptions used to determine benefit obligations as of December 31:
Discount rate	3.25%	3.50%
Rate of compensation increase	0.00%	0.00%
Weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31:
Discount rate - service cost	4.61%	4.95%	3.23%
Discount rate - interest cost	2.56%	2.49%	3.23%
Expected long-term return on plan assets	0.00%	0.00%	0.00%
Rate of compensation increase	0.00%	0.00%	0.00%
Foreign Plan [Member]
Weighted-average assumptions used to determine benefit obligations as of December 31:
Discount rate	2.58%	2.83%
Rate of compensation increase	3.63%	3.78%
Weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31:
Discount rate - service cost	1.34%	2.04%	4.12%
Discount rate - interest cost	2.75%	3.45%	4.12%
Expected long-term return on plan assets	4.40%	4.87%	5.22%
Rate of compensation increase	3.78%	3.70%	3.48%