Accumulated Other Comprehensive Loss (Schedule Of Accumulated Other Comprehensive Loss By Component) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 575,987
Other comprehensive income (loss)	(7,122)
Ending Balance	506,423
Foreign currency translation adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(36,669)
Other comprehensive income (loss)	(6,787)
Ending Balance	(43,456)
Defined benefit pension plan
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(2,647)
Other comprehensive income (loss)	207
Ending Balance	(2,440)
Derivative financial instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	0
Other comprehensive income (loss)	(798)
Ending Balance	(798)
Liquidation of non-US entity and purchase of non-controlling interests
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	338
Other comprehensive income (loss)	256
Ending Balance	594
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(38,978)
Ending Balance	$ (46,100)