v3.4.0.3
Total Equity (Preferred Stock Outstanding) (Details) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended
Mar. 31, 2016
Dec. 31, 2015
Class of Stock    
Preferred stock carrying value $ 7,520 $ 7,520
Series A Preferred Stock    
Class of Stock    
Preferred stock shares outstanding 44,000,000,000  
Liquidation preference per share $ 25,000  
Preferred stock carrying value $ 1,100 1,100
Series C Preferred Stock    
Class of Stock    
Preferred stock shares outstanding 519,882,000,000  
Liquidation preference per share $ 1,000  
Preferred stock carrying value $ 408 408
Series C Preferred Stock | MUFG    
Class of Stock    
Preferred Stock Shares Issued 1,160,791  
Preferred Stock, Value, Issued $ 911  
Preferred Stock Redemption Amount $ 503  
Preferred Stock Redemption Shares 640,909  
Convert to common shares $ 705  
Series E Preferred Stock    
Class of Stock    
Preferred stock shares outstanding 34,500,000,000  
Liquidation preference per share $ 25,000  
Preferred stock carrying value $ 862 862
Series F Preferred Stock    
Class of Stock    
Preferred stock shares outstanding 34,000,000,000  
Liquidation preference per share $ 25,000  
Preferred stock carrying value $ 850 850
Series G Preferred Stock    
Class of Stock    
Preferred stock shares outstanding 20,000,000,000  
Liquidation preference per share $ 25,000  
Preferred stock carrying value $ 500 500
Series H Preferred Stock    
Class of Stock    
Preferred stock shares outstanding 52,000,000,000  
Liquidation preference per share $ 25,000  
Preferred stock carrying value $ 1,300 1,300
Series I Preferred Stock    
Class of Stock    
Preferred stock shares outstanding 40,000,000,000  
Liquidation preference per share $ 25,000  
Preferred stock carrying value $ 1,000 1,000
Series J Preferred Stock    
Class of Stock    
Preferred stock shares outstanding 60,000,000,000  
Liquidation preference per share $ 25,000  
Preferred stock carrying value $ 1,500 $ 1,500