Annual report pursuant to Section 13 and 15(d)

Shareholders' Equity - Preferred Stock Narrative (Details)

v3.10.0.1
Shareholders' Equity - Preferred Stock Narrative (Details)
$ / shares in Units, $ in Millions
 12 Months Ended
Jul. 24, 2018
USD ($)
shares
May 16, 2018
USD ($)
shares
Mar. 15, 2018
USD ($)
shares
Dec. 31, 2018
USD ($)
d
quarterly_period
director
semi_annual_period
$ / shares
shares
Dec. 31, 2017
USD ($)
$ / shares
shares
Dec. 31, 2016
USD ($)
Class of Stock [Line Items]            
Preferred stock dividends       $ 1,451 $ 1,578 $ 1,682
Preferred stock issued (in shares) | shares       3,843,140 3,837,683  
Issuance of preferred stock       $ 4,515   $ 2,947
Preferred stock, par value (in dollars per share) | $ / shares       $ 0.01 $ 0.01  
Series FF Preferred Stock            
Class of Stock [Line Items]            
Preferred stock issued (in shares) | shares     94,000      
Per annum dividend rate     5.875% 5.875%    
Issuance of preferred stock     $ 2,350      
Series GG Preferred Stock            
Class of Stock [Line Items]            
Preferred stock issued (in shares) | shares   54,000        
Per annum dividend rate   6.00%   6.00%    
Issuance of preferred stock   $ 1,350        
Series HH Preferred Stock            
Class of Stock [Line Items]            
Preferred stock issued (in shares) | shares 34,160          
Per annum dividend rate 5.875%     5.875%    
Issuance of preferred stock $ 854          
Series D, Series I, Series K, Series M and Series 3 Preferred Stock            
Class of Stock [Line Items]            
Redemption of preferred stock       $ 4,500    
Preferred Stock, Excluding Series B, F, G and T Preferred            
Class of Stock [Line Items]            
Number of semi annual periods in arrears (or more) | semi_annual_period       3    
Number of quarterly periods in arrears (or more) | quarterly_period       6    
Number of additional directors to be elected | director       2    
Number of semi annual periods for termination (or more) | semi_annual_period       2    
Number of quarterly periods for termination (or more) | quarterly_period       4    
Series L Preferred Stock            
Class of Stock [Line Items]            
Per annum dividend rate       7.25%    
Preferred stock to be convertible into common shares (in shares) | shares       20    
Number of trading days | d       20    
Period of consecutive trading days | d       30    
Threshold percentage of common stock closing price (exceeds)       130.00%