v3.20.4
Equity - Narrative (Details)
1 Months Ended 12 Months Ended
May 04, 2020
shares
Aug. 31, 2019
$ / shares
shares
Feb. 28, 2019
USD ($)
shares
Sep. 30, 2018
$ / shares
shares
Mar. 31, 2018
USD ($)
$ / shares
shares
Dec. 31, 2020
USD ($)
employeeStockOwnershipPlan
shares
Dec. 31, 2019
USD ($)
shares
Dec. 31, 2018
USD ($)
shares
Dec. 31, 2017
USD ($)
Dec. 31, 2015
USD ($)
Equity, Class of Treasury Stock [Line Items]                    
Shares repurchased | shares           0 213,000,000 [1] 307,000,000 [2]    
Amount of remaining shares authorized in stock purchase plan, value           $ 5,300,000,000        
Preferred stock outstanding (in shares) | shares 0                  
Number of employee stock ownership plans | employeeStockOwnershipPlan           1        
Common ESOP Plan [Member]                    
Equity, Class of Treasury Stock [Line Items]                    
ESOP compensation expense           $ 19,000,000 $ 20,000,000 $ 19,000,000    
Common Stock [Member]                    
Equity, Class of Treasury Stock [Line Items]                    
Shares issued upon conversion of convertible preferred stock (in shares) | shares 1,070,369                  
December 2015 Stock Purchase Plan [Member]                    
Equity, Class of Treasury Stock [Line Items]                    
Amount of shares authorized in stock purchase plan, value                   $ 11,000,000,000
December 2017 Stock Purchase Plan [Member]                    
Equity, Class of Treasury Stock [Line Items]                    
Amount of shares authorized in stock purchase plan, value                 $ 10,000,000,000  
December 2018 Stock Purchase Plan [Member]                    
Equity, Class of Treasury Stock [Line Items]                    
Amount of shares authorized in stock purchase plan, value               $ 10,000,000,000    
Share Repurchase Agreement with Citibank [Member]                    
Equity, Class of Treasury Stock [Line Items]                    
Amount of shares authorized in stock purchase plan, value         $ 4,000,000,000          
Accelerated share repurchases, cash paid         $ 4,000,000,000          
Shares repurchased | shares       21,000,000 87,000,000          
Shares repurchased, initial price per share (in dollars per share) | $ / shares         $ 36.61          
Accelerated share repurchase, percentage of agreement         80.00%          
Accelerated share repurchase, final average price paid (in dollars per share) | $ / shares       $ 36.86            
Share Repurchase Agreement with Goldman, Sachs & Co. LLC [Member]                    
Equity, Class of Treasury Stock [Line Items]                    
Amount of shares authorized in stock purchase plan, value     $ 6,800,000,000              
Accelerated share repurchases, cash paid     $ 6,800,000,000              
Shares repurchased | shares   33,500,000 130,000,000              
Accelerated share repurchase, percentage of agreement     80.00%              
Accelerated share repurchase, final average price paid (in dollars per share) | $ / shares   $ 41.42                
[1] Represents shares purchased pursuant to the ASR with Goldman Sachs & Co. LLC entered into in February 2019, as well as open market share repurchases of $2.1 billion
[2] Represents shares purchased pursuant to the ASR with Citibank entered into in March 2018, as well as open market share repurchases of $8.2 billion