Segment Information (Net Revenues And Profit By Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012 segment		Jun. 30, 2011
Number of reportable segments					2
Net revenues	$ 615,210		$ 530,790		$ 1,204,705		$ 1,021,678
Amortization of intangible assets	(22,294)	[1]	(16,479)	[1]	(49,296)	[1]	(32,687)	[1]
Restructuring	0	[1]	0	[1]	0	[1]	(24)	[1]
Net interest and other income	3,353	[1]	5,088	[1]	7,153	[1]	12,660	[1]
Stock-based compensation	(38,262)	[1]	(20,753)	[1]	(68,819)	[1]	(38,637)	[1]
Income before income taxes	85,545		100,678		170,095		189,133
Enterprise Divisions [Member]
Net revenues	489,700		424,311		958,462		815,427
Segment profit	123,776		116,619		240,949		217,068
Online Services Division [Member]
Net revenues	125,510		106,479		246,243		206,251
Segment profit	$ 18,972		$ 16,203		$ 40,108		$ 30,753

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