Commitments And Contingencies (Reconciliation Of Contingent Consideration Liability) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Combination, Contingent Consideration, Reconciliation of Change in Liability
Balance at beginning of period	$ 12,545	$ 9,241	$ 10,840
Acquisitions	43	7,288	1,322
Payments	(4,803)	(7,682)	(4,944)
Accretion	951	1,652	1,274
Fair value adjustments	(944)	1,257	749
Net foreign currency translation adjustment	(490)	789	0
Balance at end of the period	7,302	12,545	9,241
Less current portion in accrued expenses and other current liabilities	(17)	(4,658)	(5,829)
Total long-term portion in other long-term liabilities	7,285	$ 7,887	$ 3,412
Contingent consideration, total remaining estimated payments	$ 9,100