Restructuring Charges (Schedule Of Accrued Restructuring) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 290
Restructuring charges	1,437
Cash Payment	(1,239)
Foreign Exchange Adjustments	(1)
Ending Balance	487
2018 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0
Restructuring charges	1,063
Cash Payment	(914)
Foreign Exchange Adjustments	0
Ending Balance	149
2017 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	245
Restructuring charges	340
Cash Payment	(306)
Foreign Exchange Adjustments	(1)
Ending Balance	278
2016 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	45
Restructuring charges	34
Cash Payment	(19)
Non-Cash Activity	0
Foreign Exchange Adjustments	0
Ending Balance	60
Severance [Member] | 2018 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0
Restructuring charges	765
Cash Payment	(746)
Foreign Exchange Adjustments	0
Ending Balance	19
Severance [Member] | 2017 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	47
Restructuring charges	0
Cash Payment	0
Foreign Exchange Adjustments	0
Ending Balance	47
Severance [Member] | 2016 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	29
Restructuring Reserve Accrual Adjustment	(1)
Cash Payment	(3)
Non-Cash Activity	0
Foreign Exchange Adjustments	0
Ending Balance	25
Lease Facility Costs [Member] | 2017 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0
Restructuring charges	96
Cash Payment	(96)
Foreign Exchange Adjustments	0
Ending Balance	0
Lease Facility Costs [Member] | 2016 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0
Restructuring charges	0
Cash Payment	0
Non-Cash Activity	0
Foreign Exchange Adjustments	0
Ending Balance	0
Other Exit Costs | 2018 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	0
Restructuring charges	298
Cash Payment	(168)
Foreign Exchange Adjustments	0
Ending Balance	130
Other Exit Costs | 2017 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	198
Restructuring charges	244
Cash Payment	(210)
Foreign Exchange Adjustments	(1)
Ending Balance	231
Other Exit Costs | 2016 [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	16
Restructuring charges	35
Cash Payment	(16)
Foreign Exchange Adjustments	0
Ending Balance	$ 35