Pension and Postretirement Benefits (Assumptions) (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Postretirement Medical Benefits
Weighted average assumptions used to determine Benefit Obligations:
Discount rate	3.27%	4.20%	3.48%
Weighted average assumptions used to determine net pension expense:
Discount rate	4.20%	3.48%	3.75%
United States | Pension Plan
Weighted average assumptions used to determine Benefit Obligations:
Discount rate	3.41%	4.34%	3.63%
Rate of increase in compensation levels	3.50%	3.50%	4.01%
Weighted average assumptions used to determine net pension expense:
Long-term rate of return on assets	6.00%	6.00%	6.00%
Discount rate	4.34%	3.63%	4.00%
Rate of increase in compensation levels	3.50%	4.01%	4.01%
Foreign Plan
Weighted average assumptions used to determine Benefit Obligations:
Discount rate			2.25%
Rate of increase in compensation levels	3.12%	3.28%	3.25%
Weighted average assumptions used to determine net pension expense:
Long-term rate of return on assets			3.88%
Discount rate	2.42%	2.25%	2.34%
Rate of increase in compensation levels	3.28%	3.25%	3.22%
Foreign Plan | Pension Plan
Weighted average assumptions used to determine Benefit Obligations:
Discount rate	1.61%	2.42%
Weighted average assumptions used to determine net pension expense:
Long-term rate of return on assets	3.37%	3.62%