Other Comprehensive Income (Loss) (Schedule Of Tax Effects Of The Components Of Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Other Comprehensive Income (Loss) [Abstract]
Defined benefit pension plan adjustments, Before-Tax Amount	$ 455	$ 427
Defined benefit pension plan adjustments, Tax (Expense) Benefit	(187)	(180)
Defined benefit pension plan adjustments, Net-of-Tax Amount	268	247
Foreign currency translation adjustments, Before-Tax Amount	(92)	1,604
Foreign currency translation adjustments, Tax (Expense) Benefit	38	(674)
Foreign currency translation adjustments, Net-of-Tax Amount	(54)	930
Unrealized (loss) gain in fair value of investments, Before-Tax Amount	(36)	13
Unrealized (loss) gain in fair value of investments, Tax (Expense) Benefit	15	(5)
Unrealized (loss) gain in fair value of investments, Net-of-Tax Amount	(21)	8
Unrealized loss in fair value of interest rate swap, Before-Tax Amount		(62)
Unrealized loss in fair value of interest rate swap, Tax (Expense) Benefit		27
Unrealized loss in fair value of interest rate swap, Net-of-Tax Amount		(35)
Total other comprehensive income, Before-Tax Amount	327	1,982
Total other comprehensive income, Tax (Expense) Benefit	(134)	(832)
Total other comprehensive income, net of tax	$ 193	$ 1,150

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