Segment Information (Net Revenues And Profit By Segment) (Details) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) segment	Jun. 30, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | segment				2
Net revenues		$ 796,759	$ 781,560	$ 1,557,561	$ 1,532,379
Segment profit		122,149	54,419	173,881	126,306
Restructuring		(14,534)	(4,511)	(48,485)	(14,161)
Stock-based compensation		(30,792)	(45,290)	(65,003)	(85,991)
Consolidated income before income taxes		110,727	51,028	146,324	119,783
Operating Segments [Member] | Enterprise and Service Provider Division [Member]
Segment Reporting Information [Line Items]
Net revenues		619,175	620,781	1,210,613	1,214,468
Segment profit		167,310	136,551	291,933	263,127
Operating Segments [Member] | Mobility Apps [Member]
Segment Reporting Information [Line Items]
Net revenues		177,584	160,779	346,948	317,911
Segment profit		29,883	32,509	52,347	64,931
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Amortization of intangible assets	[1]	(29,720)	(64,840)	(57,893)	(101,600)
Other	[1]	0	0	982	0
Restructuring	[1]	(14,534)	(4,511)	(48,485)	(14,161)
Net interest and other (expense) income, net	[1]	(11,420)	(3,391)	(27,557)	(6,523)
Stock-based compensation	[1]	$ (30,792)	$ (45,290)	$ (65,003)	$ (85,991)

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