Pensions and Other Postretirement Benefit Plans (Schedule of (Gains)/Losses Recognized in Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
(Gains)/losses in plan assets and benefit obligations recognized in other comprehensive income:
Settlements/curtailments	$ (1,494)		$ (51)
Asset/liability loss/(gain)	(851)	(2,955)	5,498
Amortization of actuarial (loss)	(5,175)	(5,439)	(5,102)
Amortization of prior service (cost)/credit	4,454	4,453	4,450
Pension Plans [Member]
(Gains)/losses in plan assets and benefit obligations recognized in other comprehensive income:
Settlements/curtailments	(1,494)		(51)
Asset/liability loss/(gain)	6,411	(4,408)	6,519
Amortization of actuarial (loss)	(2,219)	(2,628)	(2,283)
Amortization of prior service (cost)/credit	(34)	(36)	(38)
Currency impact	(1,389)	1,930	(1,655)
Cost/(benefit) in other comprehensive income	1,275	(5,142)	2,492
Other postretirement benefits [Member]
(Gains)/losses in plan assets and benefit obligations recognized in other comprehensive income:
Settlements/curtailments
Asset/liability loss/(gain)	(6,100)	2,743	(395)
Amortization of actuarial (loss)	(2,956)	(2,811)	(2,819)
Amortization of prior service (cost)/credit	4,488	4,488	4,488
Currency impact		2	(1)
Cost/(benefit) in other comprehensive income	$ (4,568)	$ 4,422	$ 1,273