Allocation of Purchase Price (Parenthetical) (Detail)	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Developed technology
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Weighted-average useful life (in years)	3.2	4.7	3.5
Isilon | Developed technology
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Weighted-average useful life (in years)		3.1
Isilon | Customer maintenance relationships
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Weighted-average useful life (in years)		6.6
Isilon | Customer product relationships
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Weighted-average useful life (in years)		4.3
Isilon | Tradename
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Weighted-average useful life (in years)		2.4
Data Domain | Developed technology
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Weighted-average useful life (in years)			2.6
Data Domain | Customer maintenance relationships
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Weighted-average useful life (in years)			5.8
Data Domain | Customer product relationships
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Weighted-average useful life (in years)			4.2
Data Domain | Tradename
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Weighted-average useful life (in years)			2.0