Pension and Other Postretirement Benefits (Details 4) - Pensions [Member] - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Projected benefit obligation	$ 381,064	$ 430,334
Accumulated benefit obligation	375,201	420,231
Fair value of plan assets	313,461	351,210
U.S. [Member]
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Projected benefit obligation	334,808	388,334
Accumulated benefit obligation	322,999	378,285
Fair value of plan assets	282,213	322,615
Foreign Plan [Member]
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Projected benefit obligation	46,256	42,000
Accumulated benefit obligation	52,202	41,946
Fair value of plan assets	$ 31,248	$ 28,595