Segment Information (Net Revenues And Profit By Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended						36 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009		Dec. 31, 2011
Net revenues	$ 619,366	$ 565,348	$ 530,790	$ 490,888	$ 529,724	$ 472,233	$ 458,433	$ 414,272	$ 2,206,392		$ 1,874,662		$ 1,614,088
Amortization of intangible assets									(71,131)	[1]	(64,783)	[1]	(68,889)	[1]
Restructuring									(24)	[1]	(971)	[1]	(26,473)	[1]	(27,500)
Net interest and other income									13,531	[1]	13,104	[1]	15,215	[1]
Stock-based compensation									(92,909)	[1]	(103,758)	[1]	(111,419)	[1]
Income before income taxes									430,497		333,820		193,892
Enterprise Divisions [Member]
Net revenues									1,778,646		1,514,045		1,305,911
Segment profit									504,883		403,722		308,609
Online Services Division [Member]
Net revenues									427,746		360,617		308,177
Segment profit									76,147		86,506		76,849
Restructuring									$ 0		$ (175)		$ (1,013)		$ (1,200)

[1] Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments.