Employee Stock and Benefit Plans (Narrative) (Details) (USD $)
12 Months Ended 0 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Apr. 23, 2012
Apr. 24, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term in Years, Maximum 4.81 4.81 4.78    
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term in Years, Minimum 4.78 4.78 4.65    
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum 0.00% 0.00% 0.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum 0.00% 0.00% 0.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum 0.00% 0.00% 0.00%    
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum 0.00% 0.00% 0.00%    
Expected dividend yield 0.00% 0.00% 0.00%    
Stock based compensation maximum limit 64,933,332        
Remaining Authorized Shares         $ 9,731,179
Share-based Compensation Agreements, Maximum Contractual Term 10 years        
Number of shares limit in aggregate shares made by chief executive officer 1,000,000        
Number of restricted stock shares limit in aggregate made by chief executive officer 500,000        
Share-based payment expense related to stock options 4,000,000 9,000,000 20,300,000    
Share-based payment expense related to restricted stock 10,400,000 20,000,000 22,200,000    
Employee Service Share Based Compensation Cash Received From Exercise Of Stock Options And Other Awards 86,000 1,000,000 2,000,000    
Total fair value of options vested 16,400,000 39,100,000 54,300,000    
Weighted average fair value of the stock option awards on their grant dates $ 0.01 $ 4.64 $ 7.31    
Total fair value of restricted stock vested 1,200,000 7,700,000      
Weighted average fair value of the restricted stock awards on their grant dates $ 0.85 $ 8.69 $ 16.97    
Stock Options [Member]          
Stock options, granted 1,752,921     1,752,921  
Unrecognized compensation cost 5,200,000        
Recognized over a weighted average period   1 year 3 months 8 days      
Restricted Stock [Member]          
Restricted stock, granted 3,605,538     2,271,555  
Unrecognized compensation cost $ 7,800,000        
Recognized over a weighted average period 1 year 6 months 8 days        
Restricted stock shares, vested 1,140,667        
Weighted average fair value of the restricted stock awards on their grant dates $ 16.80