Supplemental Consolidated Balance Sheet Information (Property And Equipment, Net) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 220,433	$ 210,104
Less: accumulated depreciation and amortization	(134,498)	(127,151)
Property and equipment, net	85,935	82,953
Furniture, Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	71,842	69,210
Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	85,066	83,766
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 63,525	$ 57,128