Pensions and Other Postretirement Benefit Plans (Schedule of Pension Plans with Projected Benefit Obligation and Accumulated Benefit Obligation in Excess of Plan Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Plans with projected benefit obligation in excess of plan assets:
Projected benefit obligation	$ 137,123	$ 123,261
Fair value of plan assets	100,330	86,547
Plans with accumulated benefit obligation in excess of plan assets:
Accumulated benefit obligation	134,737	120,869
Fair value of plan assets	$ 100,330	$ 86,062