Postretirement Benefits Other Than Pensions - Schedule of Amounts Recognized in Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accrued Liabilities [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	$ (2,098)	$ (2,047)
Accrued Liabilities [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	(634)	(548)
Pension Benefits Long Term [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	(32,726)	(31,830)
Pension Benefits Long Term [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	$ (23,608)	$ (17,803)