Significant Accounting Policies (Changes in Goodwill) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Goodwill [Roll Forward]
Beginning balance	$ 1,768,949		$ 1,518,219
Additions	41,011	[1]	251,468	[1]
Other	(13,109)		(738)
Ending balance	1,796,851		1,768,949
Enterprise and Service Provider division
Goodwill [Roll Forward]
Beginning balance	1,402,156		1,158,580
Additions	30,317		248,800
Other	1,896	[2]	(5,224)	[3]
Ending balance	1,434,369		1,402,156
Mobility Apps division
Goodwill [Roll Forward]
Beginning balance	366,793		359,639
Additions	10,694		2,668
Other	(15,005)	[4]	4,486	[4]
Ending balance	$ 362,482		$ 366,793

[1] Amount primarily relates to 2014 acquisitions. See Note 3 for more information regarding the Company’s acquisitions.

[2] Amount primarily relates to adjustments to purchase price allocations for certain 2013 Acquisitions.

[3] Amount primarily relates to adjustments to purchase price allocations for certain 2012 Acquisitions.

[4] Amount primarily relates to foreign currency translation.