Pension and Other Postretirement Benefits (Details 4) - Pension Plan [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Pension Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Projected benefit obligation	$ 430,334	$ 81,503
Accumulated benefit obligation	420,231	80,967
Fair value of plan assets	351,210	31,002
Total accumulated benefit obligation	457,539	485,777
Domestic Plan [Member]
Defined Benefit Plan, Pension Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Projected benefit obligation	388,334	40,572
Accumulated benefit obligation	378,285	40,090
Fair value of plan assets	322,615	4,797
Foreign Plan [Member]
Defined Benefit Plan, Pension Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Projected benefit obligation	42,000	40,931
Accumulated benefit obligation	41,946	40,877
Fair value of plan assets	$ 28,595	$ 26,205