Segment Information (Net Revenues And Profit By Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014 segment		Jun. 30, 2013
Segment Reporting Information [Line Items]
Number of reportable segments					2
Net revenues	$ 781,560		$ 730,384		$ 1,532,379		$ 1,403,283
Segment profit	54,419		75,888		126,306		132,496
Amortization of intangible assets	(64,840)	[1]	(34,860)	[1]	(101,600)	[1]	(69,987)	[1]
Restructuring Charges	(4,511)	[1]	0	[1]	(14,161)	[1]	0	[1]
Net interest and other income (expense), net	(3,391)	[1]	1,375	[1]	(6,523)	[1]	2,571	[1]
Stock-based compensation	(45,290)	[1]	(47,857)	[1]	(85,991)	[1]	(91,413)	[1]
Consolidated income before income taxes	51,028		77,263		119,783		135,067
Enterprise and Service Provider Division [Member]
Segment Reporting Information [Line Items]
Net revenues	620,781		586,526		1,214,468		1,121,859
Segment profit	136,551		132,591		263,127		245,847
SaaS Division [Member]
Segment Reporting Information [Line Items]
Net revenues	160,779		143,858		317,911		281,424
Segment profit	$ 32,509		$ 26,014		$ 64,931		$ 48,049

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