Segment Information (Net Revenues And Profit By Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Net revenues	$ 739,996	$ 619,366	$ 641,422	$ 615,210	$ 589,495	$ 565,348	$ 530,790	$ 490,888	$ 2,586,123		$ 2,206,392		$ 1,874,662
Amortization of intangible assets									(114,574)	[1]	(71,131)	[1]	(64,783)	[1]
Restructuring									0	[1]	(24)	[1]	(971)	[1]
Net interest and other income									19,451	[1]	13,531	[1]	13,104	[1]
Stock-based compensation									(149,940)	[1]	(92,909)	[1]	(103,758)	[1]
Income before income taxes									410,229		430,497		333,820
Enterprise Divisions [Member]
Net revenues									2,074,800		1,778,646		1,514,045
Segment profit									562,794		504,883		403,722
Online Services division revenues
Net revenues									511,323		427,746		360,617
Segment profit									$ 92,498		$ 76,147		$ 86,506

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