Acquisitions (Estimated Fair Values of Assets Acquired and Liabilities Assumed) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended	1 Months Ended				12 Months Ended
	Dec. 31, 2011 years	Feb. 28, 2011 Netviewer AG [Member] years	Jul. 31, 2011 Cloud.com [Member] years	Oct. 31, 2011 ShareFile [Member] years	Nov. 30, 2011 App-DNA [Member] years	Dec. 31, 2011 Ringcube and Other Acquisition [Member] years
Current assets		$ 12,082	$ 6,460	$ 2,108	$ 13,422	$ 569	[1]
Other assets		330	32	20	172	189	[1]
Property and equipment		2,350	260	197	662	0	[1]
Deferred tax assets, non-current		10,192	3,819	0	0	14,055	[1]
Intangible assets		28,806	89,000	28,200	44,760	30,600	[1]
Goodwill		98,725	100,649	49,879	58,204	15,540	[1]
Assets acquired		152,485	200,220	80,404	117,220	60,953	[1]
Current liabilities assumed		(18,144)	(1,639)	(13,234)	(9,221)	(7,150)	[1]
Long-term liabilities assumed		(11,949)	0	(149)	(905)	(636)	[1]
Deferred tax liabilities, non-current		(8,554)	(34,174)	(10,823)	(12,551)	(9,979)	[1]
Net assets acquired		$ 113,838	$ 164,407	$ 56,198	$ 94,543	$ 43,188	[1]
Intangible asset life, minimum (in years)	3	4	7	4	4	2
Intangible asset life, maximum (in years)	7	7	12	6	5	8

[1] Includes RingCube and the Other Acquisition.