Pension, Post-Retirement and Post-Employment Plans - Key Assumptions Used to Determine Net Periodic Benefit Expense (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Domestic | Pension Plan and SERP
Weighted average assumptions used to determine net periodic benefit cost:
Discount rate	3.70%	4.20%	4.60%
Rate of compensation increase	3.50%	3.50%	3.50%
Long-term rate of return on assets	5.40%	5.90%	6.50%
Domestic | Post-retirement Medical Benefits
Weighted average assumptions used to determine net periodic benefit cost:
Discount rate	3.70%	4.20%	4.40%
Foreign | Pension Plan and SERP
Weighted average assumptions used to determine net periodic benefit cost:
Discount rate	1.40%	1.60%	2.30%
Rate of compensation increase	3.40%	3.20%	3.20%
Long-term rate of return on assets	1.80%	1.70%	2.50%
Foreign | Post-retirement Medical Benefits
Weighted average assumptions used to determine net periodic benefit cost:
Discount rate	9.90%	12.20%	14.00%