Acquisitions (Narrative) (Details) (USD $)	12 Months Ended						1 Months Ended		1 Months Ended	12 Months Ended	1 Months Ended			3 Months Ended			12 Months Ended		3 Months Ended		3 Months Ended		12 Months Ended		0 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2013 Enterprise and Service Provider division	Dec. 31, 2012 Enterprise and Service Provider division	Jan. 31, 2013 Zenprise	Dec. 31, 2013 Zenprise	Jul. 31, 2012 ByteMobile	Dec. 31, 2013 ByteMobile	Apr. 30, 2012 Podio	Apr. 30, 2012 Podio Product Related Technologies	Apr. 30, 2012 Podio Other	Sep. 30, 2012 2012 Other Acquisitions acquisitions	Jun. 30, 2012 2012 Other Acquisitions acquisitions	Mar. 31, 2012 2012 Other Acquisitions	Dec. 31, 2012 2012 Other Acquisitions	Dec. 31, 2011 2012 Other Acquisitions	Sep. 30, 2012 2012 Other Acquisitions Enterprise and Service Provider division acquisitions	Mar. 31, 2012 2012 Other Acquisitions Product Related Technologies	Dec. 31, 2013 2013 Other Acquisitions	Sep. 30, 2013 2013 Other Acquisitions	Dec. 31, 2013 2013 Other Acquisitions acquisitions	Sep. 30, 2013 2013 Other Acquisitions Maximum	Jan. 08, 2014 Subsequent Event [Member] Framehawk, Inc. [Member]
Business Acquisition [Line Items]
Total consideration in business acquisitions							$ 324,000,000		$ 399,500,000		$ 43,600,000			$ 5,300,000	$ 15,400,000	$ 24,600,000					$ 5,500,000	$ 5,300,000			$ 27,900,000
Contingent consideration amount																								3,000,000
Cash acquired from the acquisition							2,900,000		5,600,000		1,700,000				200,000	600,000									300,000
Acquisition transaction costs							600,000	100,000	2,100,000		500,000			200,000	400,000	500,000					200,000	200,000	200,000		100,000
Acquisition transaction costs expensed during period																	400,000	100,000
Unvested stock options assumed in business acquisition											127,668			13,487	66,459	13,481
Stock options converted and assumed (in shares)							285,817									12,017
Number of privately-held businesses acquired														2	2				1				2
Net adjustment to preliminary purchase price allocation										3,300,000
Goodwill acquired	251,468,000	[1]	283,860,000	[1]	248,800,000	257,379,000					24,500,000					22,800,000
Finite-lived Intangible assets acquired								$ 69,200,000		$ 248,900,000	$ 24,600,000	$ 20,700,000	$ 3,900,000							$ 11,000,000	$ 11,300,000		$ 11,300,000

[1] Amount primarily relates to acquisitions. See Note 3 for more information regarding the Company’s acquisitions.