Fixed Assets (Summary Of Fixed Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Property Plant And Equipment [Abstract]
Furniture and equipment	$ 234,699		$ 234,699		$ 194,521
Building and leasehold improvements	150,768		150,768		124,390
Total	385,467		385,467		318,911
Less accumulated depreciation and amortization	(226,102)		(226,102)		(194,665)
Fixed assets, net	159,365		159,365		$ 124,246
Depreciation and amortization of furniture and equipment, and leasehold improvements	$ 6,900	$ 7,200	$ 14,899	$ 14,306