Segment Information (Net Revenues And Profit By Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015 segment		Mar. 31, 2014
Segment Reporting Information [Line Items]
Number of Reportable Segments	2
Net revenues	$ 760,802		$ 750,819
Segment profit	51,732		71,887
Amortization of intangible assets	(28,173)	[1]	(36,760)	[1]
Other	982	[1]	0	[1]
Restructuring	(33,951)	[1]	(9,650)	[1]
Net interest and other expense, net	(16,137)	[1]	(3,132)	[1]
Stock-based compensation	(34,211)	[1]	(40,701)	[1]
Consolidated income before income taxes	35,597		68,755
Enterprise and Service Provider Division [Member]
Segment Reporting Information [Line Items]
Net revenues	591,438		593,687
Segment profit	124,623		126,576
Mobility Apps [Member]
Segment Reporting Information [Line Items]
Net revenues	169,364		157,132
Segment profit	$ 22,464		$ 32,422

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