Commitments And Contingencies (Reconciliation Of Contingent Consideration Liability) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Business Combination, Contingent Consideration, Reconciliation of Change in Liability [Roll Forward]
Balance at beginning of period	$ 12,545	$ 9,241
Acquisitions	0	4,922
Payments	(1,160)	(1,884)
Accretion	337	292
Fair value adjustments	(1,248)	815
Net foreign currency translation adjustment	(151)	0
Balance at end of the period	10,323	13,386
Less current portion in accrued expenses and other current liabilities	(3,785)	(5,797)
Total long-term portion in other long-term liabilities	6,538	$ 7,589
Contingent consideration, total remaining estimated payments	$ 12,400