Segment Information (Net Revenues And Profit By Segment) (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net revenues		$ 904,763	$ 813,270	$ 796,759	$ 760,802	$ 851,483	$ 758,994	$ 781,560	$ 750,819	$ 3,275,594	$ 3,142,856	$ 2,918,434
Segment profit		$ 112,406	$ 63,798	$ 122,149	$ 51,732	$ 117,408	$ 58,597	$ 54,419	$ 71,887	350,085	302,311	380,717
Amortization and impairment of intangible assets	[1]									(239,915)	(192,325)	(139,541)
Patent litigation charge	[1]									0	(20,727)	0
Restructuring	[1]									(100,411)	(20,424)	0
Net interest and other (expense) income, net	[1]									(38,208)	(26,605)	7,173
Stock-based compensation	[1]									(147,368)	(169,287)	(183,941)
Separation Related Costs	[1]									(6,352)	0	0
Consolidated income before income taxes										311,877	275,706	387,890
Enterprise and Service Provider
Segment Reporting Information [Line Items]
Net revenues										2,544,302	2,491,294	2,335,562
Segment profit	[2]									759,614	589,076	588,138
Mobility Apps division
Segment Reporting Information [Line Items]
Net revenues										731,292	651,562	582,872
Segment profit	[2]									83,535	115,998	116,061
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Other	[1]									$ 982	$ 0	$ 0

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

[2] Effective January 1, 2015, the Company revised its methodology for allocating certain corporate costs within General and administrative expenses to more closely align these costs to the employees directly utilizing the related services within each of its reporting segments in connection with organizational structure changes that changed the manner in which shared support services are provided. This change in presentation does not affect the Company's consolidated financial position, results from operations or cash flows.