v2.4.0.6
Employee Benefit Plans (Narrative) (Details) (USD $)
In Millions, except Share data, unless otherwise specified
 0 Months Ended 12 Months Ended
Jul. 29, 2011
Jan. 29, 2011
Jul. 31, 2010
Jan. 30, 2010
Jul. 31, 2009
Jan. 31, 2009
Dec. 31, 2011
months
years
Dec. 31, 2010
Dec. 31, 2009
Maximum employee contribution percentage             90.00%    
Maximum payroll deductions, percentage             10.00%    
Employee purchase price floor, percentage             85.00%    
Offering period (months)             12    
Offering periods, frequency (months)             6    
Number of purchase periods within an offering period             2    
Purchase period (months)             6    
Purchase date, frequency (months)             6    
Increase in shares reserved for ESPP, percentage             1.00%    
Common stock issued under ESPP 54,408 77,466 60,909 146,500 108,629 84,062      
Vesting period, years             four    
Vesting period, maximum, years             10    
Equity Incentive Plan fair market value on grant date floor, percentage             100.00%    
Increase in shares reserved for Equity Incentive Plans, percentage             3.00%    
Weighted average fair value of options granted               $ 6.49 $ 3.42
Total intrinsic value of options exercised during the period             $ 3.0 $ 2.6 $ 0.1
Total fair value of options vested             5.7 6.7 7.7
In-the-money options, maximum exercise price             $ 9.31    
Options in-the-money, number             6,000,000    
Options in-the-money, exercisable, number             5,200,000    
Restricted Stock [Member]
                  
Unvested restricted stock award shares, repurchase price             $ 0.001    
Award vesting period, minimum, years             one    
Award vesting period, maximum, years             four    
Weighted average fair value of options granted             $ 12.75    
Restricted Stock Units [Member]
                  
Weighted average fair value of options granted             $ 13.99    
Total fair value of RSUs vested             $ 2.9 $ 0.5  
Restricted Stock Awards [Member]
                  
Unvested restricted common stock awards granted             151,963,000