Stock Plans (Details Textual) (USD $)
6 Months Ended 1 Months Ended 6 Months Ended 1 Months Ended 6 Months Ended 6 Months Ended 12 Months Ended 6 Months Ended
Jun. 30, 2012
2003 Stock Plan [Member]
Jun. 30, 2012
2003 Stock Plan [Member]
Maximum [Member]
Jun. 30, 2012
2003 Stock Plan [Member]
Minimum [Member]
Jun. 30, 2012
2011 Stock Option [Member]
Dec. 31, 2011
2011 Stock Option [Member]
Sep. 09, 2011
2011 Stock Option [Member]
Sep. 30, 2011
2011 Employee Stock Purchase Plan [Member]
Jun. 30, 2012
2011 Employee Stock Purchase Plan [Member]
Sep. 09, 2011
2011 Employee Stock Purchase Plan [Member]
Sep. 30, 2011
2011 Employee Stock Purchase Plan [Member]
Maximum [Member]
Period
Jun. 30, 2012
2011 Employee Stock Purchase Plan [Member]
Maximum [Member]
Jun. 30, 2012
Incapsula 2010 Share Incentive Plan [Member]
Jun. 30, 2011
Incapsula 2010 Share Incentive Plan [Member]
Mar. 31, 2010
Incapsula 2010 Share Incentive Plan [Member]
Maximum [Member]
Jun. 30, 2012
Common Stock Subject to Repurchase [Member]
Dec. 31, 2011
Common Stock Subject to Repurchase [Member]
Dec. 31, 2010
Common Stock Subject to Repurchase [Member]
Jun. 30, 2012
Common Stock Subject to Repurchase [Member]
Maximum [Member]
Jun. 30, 2012
Common Stock Subject to Repurchase [Member]
Minimum [Member]
Jun. 30, 2012
Early Exercise of Stock Options [Member]
Stock Plans (Textual) [Abstract]                                        
Maximum percentage of fair value of common stock on grant date 85.00%           85.00%                          
Minimum percentage of combined voting power 10.00%                                      
Maximum percentage of option price of fair value 110.00%                                      
Reserve of common stock issuance           1,000,000     500,000   20,000,000     4,733,333            
Increase percentage of common stock outstanding       4.00%       1.00%                        
Shares available for grant         1,886,296                              
Increase in reserve share       919,127       229,782                        
Maximum percentage of fair value of common stock on grant date       100.00%                                
Percentage in payroll of deduction base salary to acquire shares of common stock             15.00%                          
Offering period                   24 months                    
Number of purchase period for offering                   5                    
Intrinsic value of option exercised                       $ 15,400,000                
Number of years, shares reserved for issuance will increase               8 years                        
Market value of common stock                       $ 28.82                
Compensation cost related to unvested stock based awards granted, but not yet recognized                       12,000,000                
Nonvested awards, compensation cost not yet recognized, period for recognition                       2 years 6 months                
Net cash proceeds from the exercise of stock options                       1,100,000 500,000              
Capitalized stock-based compensation cost                       0 0              
Recognized stock-based compensation tax benefits                       $ 0 $ 0              
Vesting Period   10 years 4 years 10 years                           60 months 48 months  
Restricted common stock granted                             0 0 843,819      
Weighted-average grant date fair value                                 $ 1.94      
Restricted common stock unvested                             527,387          
Unvested shares                                       120,000