Pension and Postretirement Benefit Plans - Significant Weighted Average Assumptions Used in Measurement of Pension Obligations (Details) - Pension Plan [Member]	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
UNITED STATES
Pension benefit obligations:
Discount rate	4.22%	3.55%	3.92%
Net periodic benefit cost:
Discount rate	2.56%	3.24%	3.29%
Expected return on plan assets	6.00%	6.00%	6.50%
Foreign Plan [Member]
Pension benefit obligations:
Discount rate	2.42%	2.25%	2.48%
Net periodic benefit cost:
Discount rate	2.54%	2.34%	2.56%
Rate of compensation increase	3.21%	3.33%	3.12%
Expected return on plan assets	4.66%	5.92%	5.42%