Fair Value Measurements (Schedule Of Changes In Fair Value Of Level 3 Financial Assets) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease)	$ 0
Business Combination, Contingent Consideration, Liability		$ 17,450
Level 3 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease)	(600)
Other Payments to Acquire Businesses	(16,850)
Business Combination, Contingent Consideration, Liability	$ 0	$ 17,450