Fixed Assets (Schedule Of Fixed Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Property, Plant and Equipment [Abstract]
Fixed assets, at cost	$ 289,719	$ 272,177	$ 256,379
Less accumulated depreciation and amortization	139,295	125,389	122,836
Fixed assets, net	$ 150,424	$ 146,788	$ 133,543