Commitments And Contingencies (Reconciliation Of Contingent Consideration Liability) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Business Combination, Contingent Consideration, Reconciliation of Change in Liability [Roll Forward]
Balance at beginning of period	$ 9,241	$ 10,840
Acquisitions	(7,288)	(1,322)
Payments	(2,574)	(2,719)
Accretion	1,227	976
Fair value adjustments	1,204	1,046
Net foreign currency translation adjustment	659	0
Balance at end of the period	17,045	11,465
Less current portion in accrued expenses and other current liabilities	(6,649)	(4,984)
Total long-term portion in other long-term liabilities	10,396	$ 6,481
Contingent consideration, total remaining estimated payments	$ 20,200