Acquisitions (Schedule of Contingent Consideration Liability) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2017	Sep. 30, 2016
Acquisitions [Abstract]
Beginning Balance			$ 2,211	$ 2,211
Net decrease in estimated fair value of contingent consideration included in Administrative expenses	$ (1,580)	$ (631)		(2,211)	$ (1,000)
Ending Balance