Income Taxes (Schedule Of Components Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Abstract]
Deferred tax assets, Allowance for doubtful accounts	$ 8,886	$ 11,979
Deferred tax assets, Accrued vacation and bonus	6,631	9,955
Deferred tax assets, Deferred rent	17,354	17,210
Deferred tax assets, Share-based compensation	25,948	23,506
Deferred tax assets, Notes receivable from employees	27,900	25,107
Deferred tax assets, Foreign tax credits		6,478
Deferred tax assets, Deferred compensation	2,602	681
Deferred tax assets, Convertible debt	38	105
Deferred tax assets, Swap termination premium	2,285
Deferred Tax Assets, Net operating loss carryforwards	5,528
Deferred tax assets, Other - net	366	864
Total deferred tax assets:	97,538	95,885
Deferred tax liabilities, Revenue recognition	(33,462)	(35,940)
Deferred tax liabilities, Property, equipment and capitalized software	(1,383)	(2,115)
Deferred tax liabilities, Goodwill and other intangible asset amortization	(160,868)	(142,182)
Deferred tax liabilities, Currency translation adjustment		(2,676)
Deferred tax assets, Discount on long term debt	(1,264)
Total deferred tax liabilities:	(196,977)	(182,913)
Net deferred tax assets (liabilities):	(100,325)	(87,028)
Valuation allowance	$ (886)