Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation and Employee Benefit Plans (Details Textual)

v2.4.0.6
Stock-Based Compensation and Employee Benefit Plans (Details Textual) (USD $)
In Millions, except Share data, unless otherwise specified
6 Months Ended 6 Months Ended 6 Months Ended 6 Months Ended 6 Months Ended 6 Months Ended
Jun. 30, 2012
Employee
Dec. 31, 2011
Jun. 30, 2012
Class A Common Stock [Member]
Votes
Dec. 31, 2011
Class A Common Stock [Member]
Jun. 30, 2012
Common Class B [Member]
Votes
Dec. 31, 2011
Common Class B [Member]
Jun. 30, 2012
Restricted Stock Units [Member]
Jun. 30, 2011
Restricted Stock Units [Member]
May 31, 2012
Restricted Stock Units [Member]
Class A Common Stock [Member]
Jun. 30, 2012
Restricted Stock Awards [Member]
Jun. 30, 2011
Restricted Stock Awards [Member]
Dec. 31, 2011
Equity Incentive Plan [Member]
Jun. 30, 2012
Employee Stock Purchase Plan [Member]
Mar. 31, 2012
Employee Stock Purchase Plan [Member]
Dec. 31, 2011
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                              
Weighted-average grant date fair value per share             $ 5.90 $ 9.02   $ 5.90 $ 0.00        
Shares authorized for issuance                       1,329,000     415,000
Contribution of earnings by employees                           15.00%  
Percentage of purchase of common stock                         85.00%    
Percentage of common stock on the date of purchase                         85.00%    
Common stock, shares authorized 550,000,000 550,000,000 500,000,000 500,000,000 500,000,000 500,000,000                  
Voting rights per share     1   10                    
Number of convertible common stock     1                        
Eligible options to purchase shares     1,327,171   591,242                    
Eligible employees to purchase common Stock 148                            
Company's Class A common stock issuable upon vesting of RSU                 1            
Period of options granted 4 years           3 years                
Stock-Based Compensation and Employee Benefit Plans (Textual) [Abstract]                              
Exercise price per share $ 5                            
Restricted stock units Issued 959,222                            
Vesting period for new restricted stock units 4 years           3 years                
Percentage of fair value market of common stock 100.00%                            
Term of option granted, minimum 7 years                            
Term of option granted, maximum 10 years                            
Incremental value attributed to the modified options $ 1.8                            
Share based compensation expense Exchange Offer $ 7.3