Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Significant Accounting Policies [Line Items]
Percentage of ownership interest in VMware	80.00%	80.00%
Net losses from foreign currency transactions	$ (12.8)	$ (4.5)	$ (21.2)
Unamortized software development costs	665.4	566.0
Amortization expense for software development costs	380.3	314.6	283.0
Capitalized amounts for software development costs	479.7	399.5	329.1
Advertising costs	44.4	40.1	23.5
Liquid investments, maturity	90 days	90 days
Total cash equivalents at fair value	1,434.8	2,584.4
Purchased intangible assets, estimated useful lives, minimum (in years)	1
Purchased intangible assets, estimated useful lives, maximum (in years)	17
Interest Rate Swap
Significant Accounting Policies [Line Items]
Notional amount of cash flow hedges		900.0
Realized loss on replaced interest rate swap contracts	141.0
Software Development
Significant Accounting Policies [Line Items]
Minimum useful life (in years)	1.5
Maximum useful life (in years)	2
Cash Flow Hedging
Significant Accounting Policies [Line Items]
Contract maturity	6 months
Notional amount of cash flow hedges	$ 194.0	$ 152.0	$ 108.0
Foreign Exchange
Significant Accounting Policies [Line Items]
Contract maturity	1 year