Other Comprehensive Income (Loss) (Accumulated Other Comprehensive Loss In Equity) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Comprehensive Income (Loss), before Tax [Abstract]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	$ 14,377
Unrealized gain on post-retirement benefit obligations	16,939	$ 20,055
Accumulated Other Comprehensive Income (Loss), Unrealized Loss on Pension Obligation	(654)
Unrealized gain (loss) on marketable securities	0	3
Unrealized gain (loss) on hedging instruments	(793)	(9,446)
Accumulated other comprehensive income (loss)	$ 29,869	$ 10,612