Fixed Assets (Schedule Of Fixed Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Fixed assets, at cost	$ 313,057	$ 291,776	$ 289,719
Less accumulated depreciation and amortization	159,890	141,176	139,295
Fixed assets, net	$ 153,167	$ 150,600	$ 150,424