Commitments And Contingencies (Reconciliation Of Contingent Consideration Liability) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Combination, Contingent Consideration, Reconciliation of Change in Liability
Balance at beginning of period	$ 4,396	$ 7,302	$ 12,545
Acquisitions	2,796	0	43
Payments	(1,633)	(10)	(4,803)
Accretion	601	792	951
Fair value adjustments	(1,947)	(3,691)	(944)
Net foreign currency translation adjustment	396	3	(490)
Balance at end of the period	4,609	4,396	7,302
Less current portion in accrued expenses and other current liabilities	(2,683)	(2,351)	(17)
Total long-term portion in other long-term liabilities	1,926	$ 2,045	$ 7,285
Contingent consideration, total remaining estimated payments	$ 5,600