Equity Based Compensation (Details Textual) (USD $)
 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2012
2011 Equity Compensation Plan [Member]
Jun. 30, 2012
Reorganization Related [Member]
Jun. 30, 2011
Reorganization Related [Member]
Jun. 30, 2012
Reorganization Related [Member]
Jun. 30, 2011
Reorganization Related [Member]
Jun. 30, 2012
Performance Based Stock Units [Member]
Jun. 30, 2012
Performance Based Stock Units [Member]
Dec. 31, 2011
Performance Based Stock Units [Member]
Jun. 30, 2012
Service Based Stock Unit [Member]
Jun. 30, 2012
Service Based Stock Unit [Member]
Dec. 31, 2011
Service Based Stock Unit [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Equity interests awarded under the 2011 Plan   $ 0                    
Equity interests available under the 2011 Plan   13,142,813                    
Number of reorganization related performance units eligible to vest during the current year 4,500,000                      
Expense recognized for the performance-based awards eligible to vest during future years         0              
Weighted average fair value of the awards granted               $ 0.00     $ 13.45  
Weighted average value of the awards             $ 12.00 $ 12.00 $ 12.00 $ 12.00 $ 12.00 $ 12.00
Compensation expense related to the amended vesting terms of ownership interests     24,000,000 300,000 27,700,000 600,000 21,300,000 21,400,000   2,700,000 6,400,000  
Expense attributable to performance-based awards eligible to vest             21,200,000 21,200,000        
Forfeitures of service-based stock unit         65,740              
Unrecognized compensation expense related to unvested awards             170,200,000 170,200,000   27,600,000 27,600,000  
Weighted average period of unrecognized compensation expense               1 year 7 months 6 days     1 year 8 months 12 days  
Unrecognized compensation expense related to unvested reorganization-related performance-based awards             169,800,000 169,800,000        
Total number of reorganization related performance units             13,500,000 13,500,000        
Weighted average fair value of the awards with service inception $ 14.23                      
Equity Based Compensation (Textual) [Abstract]                        
The aggregate intrinsic value of stock units that vested $ 900,000                      
Weighted average fair value of the awards with service inception $ 14.23