v3.21.2
Shareholders' Equity - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
1 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended
Dec. 30, 2021
Dec. 02, 2021
Oct. 31, 2021
Oct. 13, 2021
Oct. 07, 2021
Apr. 30, 2021
Sep. 30, 2021
Jun. 30, 2021
Mar. 31, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Equity [Line Items]                          
Common stock, shares authorized             4,000,000,000.00       4,000,000,000.00   4,000,000,000.00
Nonvoting common stock, shares authorized             200,000,000       200,000,000   200,000,000
Nonvoting common stock, par value             $ 0.01       $ 0.01   $ 0.01
Shares remitted by employees to satisfy minimum statutory employee tax withholding                     1,830    
Remitted Shares, Total                     $ 0.5    
Amount of share-based awards cancelled to satisfy minimum statutory employee tax withholding requirements                     3,400,000    
Value of share-based awards cancelled to satisfy minimum statutory employee tax withholding requirements                     $ 983.0    
Dividends declared per common share       $ 2.00     $ 2.00     $ 1.25 $ 4.50 $ 3.75  
Dividends payable date declared       Oct. 13, 2021                  
Dividends payable date to be paid Dec. 30, 2021                        
Date of dividends declared on preferred shares         Oct. 07, 2021                
Redemption Value             $ 9,953.0       $ 9,953.0    
Subsequent Event [Member]                          
Equity [Line Items]                          
Dividends payable date of record   Dec. 02, 2021                      
Series A Preferred Stock [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared             $ 239.58     236.98 $ 710.93 708.34  
Depositary shares per share             1,000       1,000    
Redemption Value             $ 750.0       $ 750.0    
Liquidation preference per share             $ 25,000       $ 25,000    
Series A Preferred Stock [Member] | Subsequent Event [Member] | Group Inc. [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared         $ 239.58                
Series C Preferred Stock [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared             $ 255.56     252.78 $ 758.34 755.56  
Depositary shares per share             1,000       1,000    
Redemption Value             $ 200.0       $ 200.0    
Liquidation preference per share             $ 25,000       $ 25,000    
Series C Preferred Stock [Member] | Subsequent Event [Member] | Group Inc. [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared         255.56                
Series D Preferred Stock [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared             $ 255.56     252.78 $ 758.34 755.56  
Depositary shares per share             1,000       1,000    
Redemption Value             $ 1,350.0       $ 1,350.0    
Liquidation preference per share             $ 25,000       $ 25,000    
Series D Preferred Stock [Member] | Subsequent Event [Member] | Group Inc. [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared         255.56                
Series J Preferred Stock [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared             $ 343.75     343.75 $ 1,031.25 1,031.25  
Depositary shares per share             1,000       1,000    
Redemption Value             $ 1,000.0       $ 1,000.0    
Liquidation preference per share             $ 25,000       $ 25,000    
Series J Preferred Stock [Member] | Subsequent Event [Member] | Group Inc. [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared         343.75                
Series K Preferred Stock [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared             $ 398.44     398.44 $ 1,195.32 1,195.32  
Depositary shares per share             1,000       1,000    
Redemption Value             $ 700.0       $ 700.0    
Liquidation preference per share             $ 25,000       $ 25,000    
Series K Preferred Stock [Member] | Subsequent Event [Member] | Group Inc. [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared         398.44                
Series L Preferred Stock [Member]                          
Equity [Line Items]                          
Number of shares redeemed                         14,000
Dividend rate                         5.70%
Amount of redeemed                         $ 350.0
Preferred Stock, Redemption Price Per Share                         $ 25,000
Difference between the redemption value of Preferred Stock and the net carrying value at the time of redemption                         $ 1.0
Preferred stock dividends declared                       361.54  
Series M Preferred Stock [Member]                          
Equity [Line Items]                          
Dividend rate                 5.375%        
Amount of redeemed                 $ 2,000.0        
Preferred Stock, Redemption Price Per Share                 $ 25,000        
Difference between the redemption value of Preferred Stock and the net carrying value at the time of redemption                 $ 21.0        
Preferred stock dividends declared                   279.17   951.05  
Series N Preferred Stock [Member]                          
Equity [Line Items]                          
Dividend rate               6.30%          
Difference between the redemption value of Preferred Stock and the net carrying value at the time of redemption               $ 20.0          
Preferred stock dividends declared                   393.75 787.50 1,181.25  
Redemption Value               $ 675.0          
Liquidation preference per share               $ 25,000          
Series O Preferred Stock [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared                     $ 662.50 662.50  
Depositary shares per share             25       25    
Redemption Value             $ 650.0       $ 650.0    
Liquidation preference per share             $ 25,000       $ 25,000    
Series O Preferred Stock [Member] | Subsequent Event [Member] | Group Inc. [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared         662.50                
Series P Preferred Stock [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared                     $ 625.00 625.00  
Depositary shares per share             25       25    
Redemption Value             $ 1,500.0       $ 1,500.0    
Liquidation preference per share             $ 25,000       $ 25,000    
Series P Preferred Stock [Member] | Subsequent Event [Member] | Group Inc. [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared         625.00                
Series E Preferred Stock [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared             $ 1,022.22     1,022.22 $ 3,044.44 3,044.44  
Redemption Value             $ 767.0       $ 767.0    
Liquidation preference per share             $ 100,000       $ 100,000    
Series E Preferred Stock [Member] | Subsequent Event [Member] | Group Inc. [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared         1,011.11                
Series F Preferred Stock [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared             $ 1,022.22     $ 1,022.22 $ 3,044.44 $ 3,044.44  
Redemption Value             $ 161.0       $ 161.0    
Liquidation preference per share             $ 100,000       $ 100,000    
Series F Preferred Stock [Member] | Subsequent Event [Member] | Group Inc. [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared         1,011.11                
Series T Preferred Stock [Member]                          
Equity [Line Items]                          
Dividend rate           3.80%              
Preferred stock shares issued           27,000              
Depositary shares per share             25       25    
Redemption Value             $ 675.0       $ 675.0    
Liquidation preference per share             $ 25,000       $ 25,000    
Series T Preferred Stock [Member] | Subsequent Event [Member] | Group Inc. [Member]                          
Equity [Line Items]                          
Preferred stock dividends declared         $ 511.94                
Series V Preferred Stock [Member] | Subsequent Event [Member]                          
Equity [Line Items]                          
Dividend rate     4.125%                    
Preferred stock shares issued     30,000                    
Depositary shares per share     25                    
Non cumulative preferred stock fixed rate percentage     4.125%                    
Preferred stock dividend rate percentage description     (ii) 2.949% per annum plus the five-year treasury rate.                    
Preferred stock, dividend payment terms     semi-annually                    
Liquidation preference per share     $ 25,000