Fixed Assets (Schedule Of Fixed Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Property, Plant and Equipment [Abstract]
Fixed assets, at cost	$ 284,660	$ 272,177	$ 245,257
Less accumulated depreciation and amortization	136,021	125,389	118,734
Fixed assets, net	$ 148,639	$ 146,788	$ 126,523