Commitments And Contingencies (Reconciliation Of Contingent Consideration Liability) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Combination, Contingent Consideration, Reconciliation of Change in Liability
Balance at beginning of period		$ 10,840	$ 8,129	$ 7,414
Acquisitions		1,322	4,766	3,370
Payments		(4,944)	(3,974)	(3,739)
Accretion		1,274	1,196	1,075
Fair value adjustments	$ 749	749	723	9
Balance at end of the period	9,241	9,241	10,840	8,129
Less current portion in accrued expenses and other current liabilities	(5,829)	(5,829)	(3,877)	(3,622)
Total long-term portion in other long-term liabilities	3,412	$ 3,412	$ 6,963	$ 4,507
Contingent consideration, total remaining estimated payments	$ 11,600