Pension and Other Postretirement Benefits (Details 3) - Pension Plan [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation, related to pension plans with benefit obligations in excess of plan assets	$ 430,334	$ 352,251
Fair value of plan assets, related to pension plans with benefit obligations in excess of plan assets	351,210	293,292
Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation, related to pension plans with benefit obligations in excess of plan assets	388,334	311,320
Fair value of plan assets, related to pension plans with benefit obligations in excess of plan assets	322,615	267,087
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation, related to pension plans with benefit obligations in excess of plan assets	42,000	40,931
Fair value of plan assets, related to pension plans with benefit obligations in excess of plan assets	$ 28,595	$ 26,205