Annual report pursuant to Section 13 and 15(d)

SHAREHOLDERS' EQUITY (Details)

v3.20.4
SHAREHOLDERS' EQUITY (Details)
$ / shares in Units, $ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2021
USD ($)
shares
Sep. 30, 2020
USD ($)
$ / shares
shares
Jun. 30, 2020
USD ($)
$ / shares
shares
Dec. 31, 2020
USD ($)
$ / shares
Rate
shares
Dec. 31, 2019
USD ($)
$ / shares
shares
Dec. 31, 2018
USD ($)
$ / shares
Feb. 02, 2021
USD ($)
$ / shares
Feb. 27, 2018
$ / shares
Class of Stock [Line Items]                
Total Shares Outstanding | shares       750,500 740,500      
Carrying Amount       $ 2,191        
Preferred Stock, Value, Issued       2,191 $ 1,203      
Amount       (100) (74) $ (70)    
Retained Earnings                
Class of Stock [Line Items]                
Amount       $ (100) $ (74) $ (70)    
Series B                
Class of Stock [Line Items]                
Total Shares Outstanding | shares       35,500        
Carrying Amount       $ 23        
Preferred stock, dividend percentage       3-mo. LIBOR + 270 bps        
Preferred Stock, Redemption Date       Jan. 15, 2017        
Series B | Retained Earnings                
Class of Stock [Line Items]                
Cash Dividend Declared Per Share | $ / shares       $ 35.91 $ 51.22 $ 49.11    
Amount       $ (1) $ (2) $ (3)    
Series D                
Class of Stock [Line Items]                
Total Shares Outstanding | shares       400,000        
Carrying Amount       $ 386        
Preferred stock, dividend rate percentage | Rate       6.25%        
Preferred Stock, Redemption Date       Apr. 15, 2021        
Series D | Retained Earnings                
Class of Stock [Line Items]                
Cash Dividend Declared Per Share | $ / shares       $ 62.50 $ 62.50 $ 62.50    
Amount       $ (37) $ (37) $ (37)    
Series D                
Class of Stock [Line Items]                
Total Shares Outstanding | shares       200,000        
Carrying Amount       $ 199        
Preferred stock, dividend rate percentage | Rate       6.25%        
Preferred Stock, Redemption Date       Apr. 15, 2021        
Series C                
Class of Stock [Line Items]                
Total Shares Outstanding | shares       100,000        
Carrying Amount       $ 100        
Preferred stock, dividend rate percentage | Rate       5.875%        
Preferred Stock, Redemption Date       Oct. 15, 2021        
Series C | Retained Earnings                
Class of Stock [Line Items]                
Cash Dividend Declared Per Share | $ / shares       $ 58.76 $ 58.76 $ 58.76    
Amount       $ (6) $ (6) $ (6)    
Series E                
Class of Stock [Line Items]                
Total Shares Outstanding | shares       5,000        
Carrying Amount       $ 495        
Preferred stock, dividend rate percentage | Rate       5.70%        
Preferred Stock, Redemption Date       Apr. 15, 2023        
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares               $ 100,000
Series E | Retained Earnings                
Class of Stock [Line Items]                
Cash Dividend Declared Per Share | $ / shares       $ 5,700.00 $ 5,700.00 $ 4,892.50    
Amount       $ (29) $ (29) $ (24)    
Series F                
Class of Stock [Line Items]                
Total Shares Outstanding | shares       5,000        
Carrying Amount       $ 494        
Preferred stock, dividend rate percentage     5.625% 5.625%        
Preferred Stock, Redemption Date       Jul. 15, 2030        
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares     $ 100,000          
Preferred Stock, Value, Issued     $ 500          
Depositary Shares, Issued | shares     500,000          
Preferred Stock, Par or Stated Value Per Share | $ / shares     $ 10,000.00          
Payments of Stock Issuance Costs     $ 6          
Depositary Shares, Liquidation Preference Per Share | $ / shares   $ 1,000            
Depository share, percent interest in preferred stock       0.01        
Series F | Retained Earnings                
Class of Stock [Line Items]                
Cash Dividend Declared Per Share | $ / shares       $ 3,468.75        
Amount       $ (17)        
Series G                
Class of Stock [Line Items]                
Total Shares Outstanding | shares       5,000        
Carrying Amount       $ 494        
Preferred stock, dividend rate percentage   4.45%   4.45%        
Preferred Stock, Redemption Date       Oct. 15, 2027        
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares   $ 100,000            
Preferred Stock, Value, Issued   $ 500            
Depositary Shares, Issued | shares   500,000            
Preferred Stock, Par or Stated Value Per Share | $ / shares   $ 10,000.00            
Payments of Stock Issuance Costs   $ 6            
Depositary Shares, Liquidation Preference Per Share | $ / shares   $ 1,000            
Depository share, percent interest in preferred stock       0.01        
Series G | Retained Earnings                
Class of Stock [Line Items]                
Cash Dividend Declared Per Share | $ / shares       $ 1,915.97        
Amount       $ (10)        
Preferred Stock                
Class of Stock [Line Items]                
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares       $ 1,000        
Series H Preferred Stock | Subsequent Event [Member]                
Class of Stock [Line Items]                
Preferred stock, dividend rate percentage 4.50%              
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares             $ 1,000  
Preferred Stock, Value, Issued             $ 500  
Depositary Shares, Issued | shares 20,000,000              
Preferred Stock, Par or Stated Value Per Share | $ / shares             $ 10,000.00  
Payments of Stock Issuance Costs $ 16              
Depositary Shares, Liquidation Preference Per Share | $ / shares             $ 25  
Depository share, percent interest in preferred stock             0.025