Acquisitions (Estimated Fair Values Of Assets Acquired And Liabilities Assumed) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended		6 Months Ended
	Jun. 30, 2012 Y	Jun. 30, 2012 Netviewer AG [Member]	Jun. 30, 2012 Podio [Member] Y	Jun. 30, 2012 2012 Acquisition [Member] Y	Jul. 31, 2011 Cloud.Com [Member]
Current assets			$ 1,906	$ 1,801
Other assets			33	75
Property and equipment			0	209
Intangible assets			24,600	25,403
Goodwill		98,700	25,503	42,326	100,600
Assets acquired			52,042	69,814
Current liabilities assumed			(609)	(6,946)
Long-term liabilities assumed			0	(7,760)
Deferred tax liabilities, non-current			(6,150)	(10,031)
Net assets acquired			$ 45,283	$ 45,077
Intangible asset life, minimum (in years)	3		4	3
Intangible asset life, maximum (in years)	7		5	5