Acquisitions - Aggregate Allocation of the Purchase Price of Acquisitions to Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified		12 Months Ended		12 Months Ended		12 Months Ended				12 Months Ended		12 Months Ended			12 Months Ended		12 Months Ended			12 Months Ended		12 Months Ended
	Dec. 31, 2012 2012 Acquisitions, excluding Nicira	Dec. 31, 2012 All 2011 Acquisitions	Dec. 31, 2011 All 2011 Acquisitions	Dec. 31, 2012 2010 Acquisitions, excluding Isilon	Dec. 31, 2010 2010 Acquisitions, excluding Isilon	Dec. 31, 2012 2012 Acquisitions	Dec. 31, 2012 Purchased / Developed technology 2012 Acquisitions, excluding Nicira	Dec. 31, 2012 Purchased / Developed technology All 2011 Acquisitions	Dec. 31, 2011 Purchased / Developed technology All 2011 Acquisitions	Dec. 31, 2012 Purchased / Developed technology 2010 Acquisitions, excluding Isilon	Dec. 31, 2010 Purchased / Developed technology 2010 Acquisitions, excluding Isilon	Dec. 31, 2012 Customer relationships 2012 Acquisitions, excluding Nicira	Dec. 31, 2012 Customer relationships All 2011 Acquisitions	Dec. 31, 2011 Customer relationships All 2011 Acquisitions	Dec. 31, 2012 Customer relationships 2010 Acquisitions, excluding Isilon	Dec. 31, 2010 Customer relationships 2010 Acquisitions, excluding Isilon	Dec. 31, 2012 Tradename and trademark 2012 Acquisitions, excluding Nicira	Dec. 31, 2012 Tradename and trademark All 2011 Acquisitions	Dec. 31, 2011 Tradename and trademark All 2011 Acquisitions	Dec. 31, 2012 Tradename and trademark 2010 Acquisitions, excluding Isilon	Dec. 31, 2010 Tradename and trademark 2010 Acquisitions, excluding Isilon	Dec. 31, 2012 Other 2010 Acquisitions, excluding Isilon	Dec. 31, 2010 Other 2010 Acquisitions, excluding Isilon
Purchase Price Allocation, Intangible Assets
Intangible assets	$ 311,440		$ 157,100		$ 249,139	$ 311,400	$ 254,557		$ 97,500		$ 158,860	$ 54,713		$ 58,400		$ 74,280	$ 2,170		$ 1,200		$ 12,620		$ 3,379
Parenthetical
Weighted-average useful life		3 years 6 months		4 years 7 months 6 days		5 years	4 years 9 months 24 days	3 years 2 months 12 days		4 years 8 months 12 days		6 years 1 month 0 days	4 years		6 years 4 months 24 days		3 years 5 months 0 days	2 years 7 months 6 days		2 years 6 months		2 years 1 month 6 days