Segment Information (Net Revenues And Profit By Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012 segment		Sep. 30, 2011
Number of reportable segments					2
Net revenues	$ 641,422		$ 565,348		$ 1,846,127		$ 1,587,026
Amortization of intangible assets	(32,768)	[1]	(19,109)	[1]	(82,064)	[1]	(51,796)	[1]
Restructuring	0	[1]	0	[1]	0	[1]	(24)	[1]
Net interest and other income	8,483	[1]	(1,861)	[1]	15,636	[1]	10,799	[1]
Stock-based compensation	(40,103)	[1]	(24,954)	[1]	(108,922)	[1]	(63,591)	[1]
Income before income taxes	90,898		102,818		260,993		291,951
Enterprise Divisions [Member]
Net revenues	511,763		455,790		1,470,225		1,271,217
Segment profit	130,566		124,835		371,515		341,903
Online Services Division [Member]
Net revenues	129,659		109,558		375,902		315,809
Segment profit	$ 24,720		$ 23,907		$ 64,828		$ 54,660

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