Acquisitions (Schedule Of Identifiable Intangible Assets Purchased) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2011 years
Netviewer AG [Member]
Identifiable intangible assets purchased	$ 28,806
Netviewer AG [Member] | Trade Names [Member]
Identifiable intangible assets purchased	541
Weighted Average Life (in years)	4.0
Netviewer AG [Member] | Customer Relationships [Member]
Identifiable intangible assets purchased	25,019
Weighted Average Life (in years)	7.0
Netviewer AG [Member] | Core And Product Technologies [Member]
Identifiable intangible assets purchased	3,246
Weighted Average Life (in years)	4.0
Netviewer AG [Member] | Domain Name [Member]
Identifiable intangible assets purchased	0
Netviewer AG [Member] | Noncompete Agreements [Member]
Identifiable intangible assets purchased	0
Cloud.Com [Member]
Identifiable intangible assets purchased	89,000
Cloud.Com [Member] | Trade Names [Member]
Identifiable intangible assets purchased	6,000
Weighted Average Life (in years)	12.0
Cloud.Com [Member] | Customer Relationships [Member]
Identifiable intangible assets purchased	7,000
Weighted Average Life (in years)	8.0
Cloud.Com [Member] | Core And Product Technologies [Member]
Identifiable intangible assets purchased	58,000
Weighted Average Life (in years)	7.0
Cloud.Com [Member] | Domain Name [Member]
Identifiable intangible assets purchased	18,000
Weighted Average Life (in years)	12.0
Cloud.Com [Member] | Noncompete Agreements [Member]
Identifiable intangible assets purchased	0
Other Acquisition [Member]
Identifiable intangible assets purchased	30,600
Other Acquisition [Member] | Trade Names [Member]
Identifiable intangible assets purchased	60
Weighted Average Life (in years)	2.0
Other Acquisition [Member] | Customer Relationships [Member]
Identifiable intangible assets purchased	3,200
Weighted Average Life (in years)	5.3
Other Acquisition [Member] | Core And Product Technologies [Member]
Identifiable intangible assets purchased	26,000
Weighted Average Life (in years)	5.0
Other Acquisition [Member] | Domain Name [Member]
Identifiable intangible assets purchased	0
Other Acquisition [Member] | Noncompete Agreements [Member]
Identifiable intangible assets purchased	$ 1,340
Weighted Average Life (in years)	3.8