Annual report pursuant to Section 13 and 15(d)

Shareholders' Equity - Preferred Stock Narrative (Details)

v3.19.3.a.u2
Shareholders' Equity - Preferred Stock Narrative (Details)
$ / shares in Units, $ in Millions
 12 Months Ended
Jan. 27, 2020
USD ($)
Jan. 24, 2020
USD ($)
shares
Sep. 17, 2019
USD ($)
shares
Jun. 25, 2019
USD ($)
shares
Jun. 20, 2019
USD ($)
shares
Dec. 31, 2019
USD ($)
semi_annual_period
director
Days
quarterly_period
$ / shares
shares
Dec. 31, 2018
USD ($)
$ / shares
shares
Dec. 31, 2017
USD ($)
Class of Stock [Line Items]                
Preferred stock dividends           $ 1,432 $ 1,451 $ 1,578
Preferred stock issued (in shares) | shares           3,887,440 3,843,140  
Issuance of preferred stock           $ 3,643 $ 4,515  
Preferred stock, par value (in dollars per share) | $ / shares           $ 0.01 $ 0.01  
Series JJ Preferred Stock                
Class of Stock [Line Items]                
Preferred stock issued (in shares) | shares         40,000      
Per annum dividend rate         5.125% 5.125%    
Issuance of preferred stock         $ 1,000      
Series KK Preferred Stock                
Class of Stock [Line Items]                
Preferred stock issued (in shares) | shares       55,900        
Per annum dividend rate       5.375%   5.375%    
Issuance of preferred stock       $ 1,400        
Series LL Preferred Stock                
Class of Stock [Line Items]                
Preferred stock issued (in shares) | shares     52,400          
Per annum dividend rate     5.00%     5.00%    
Issuance of preferred stock     $ 1,300          
Series V Preferred Stock And Series W Preferred Stock                
Class of Stock [Line Items]                
Redeemed preferred stock           $ 2,600    
Series Y Preferred Stock                
Class of Stock [Line Items]                
Per annum dividend rate           6.50%    
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 | Days           20    
Period of consecutive trading days | Days           30    
Threshold percentage of common stock closing price (exceeds)           130.00%    
Subsequent Event | Series MM Preferred Stock                
Class of Stock [Line Items]                
Preferred stock issued (in shares) | shares   44,000            
Per annum dividend rate   4.30%            
Issuance of preferred stock   $ 1,100            
Subsequent Event | Series Y Preferred Stock                
Class of Stock [Line Items]                
Redeemed preferred stock $ 1,100