v3.26.1
Preferred Stock and Common Stock, Preferred Stock (Details)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2026
USD ($)
vote
shares
Mar. 31, 2025
USD ($)
Dec. 31, 2025
USD ($)
shares
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]      
Preferred stock, shares authorized and designated 4,611,900   4,662,300
Preferred stock, shares issued and outstanding 4,550,346   4,600,746
Preferred stock, liquidation preference, value | $ $ 16,116   $ 17,376
Preferred stock, carrying value | $ $ 15,348   $ 16,608
Detail of Preferred Stock [Abstract]      
Voting rights If issued, preference shares would be limited to one vote per share    
Number of additional common stock shares per preferred share 16.5916   16.5916
Preferred stock, convertible, settlement method [Extensible Enumeration] Net Combination Settlement [Member]   Net Combination Settlement [Member]
Preferred stock, convertible, control of rights [Fixed List] Holder   Holder
Preferred stock, no voting rights [Member]      
Detail of Preferred Stock [Abstract]      
Preferred shares authorized 20,000,000    
Preferred stock, par or stated value | $ $ 0    
Preferred stock, voting rights [Member]      
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]      
Preferred stock, shares issued and outstanding 0    
Detail of Preferred Stock [Abstract]      
Preferred shares authorized 4,000,000    
Preferred stock, par or stated value | $ $ 0    
Number of votes per share | vote 1    
Dividend Equalization Preferred Shares (DEP) [Member]      
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]      
Preferred stock, shares authorized and designated 97,000   97,000
Preferred stock, shares issued and outstanding 96,546   96,546
Preferred stock, liquidation preference, value | $ $ 0   $ 0
Preferred stock, carrying value | $ $ 0   $ 0
Series L - 7.50% Non-Cumulative Perpetual Convertible Class A Preferred Stock [Member]      
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]      
Preferred stock, shares authorized and designated 4,025,000   4,025,000
Preferred stock, shares issued and outstanding 3,967,900   3,967,900
Preferred stock, liquidation preference, value | $ $ 3,968   $ 3,968
Preferred stock, carrying value | $ $ 3,200   $ 3,200
Preferred stock, dividend rate (percent) 7.50%   7.50%
Detail of Preferred Stock [Abstract]      
Number of common stock shares per preferred share 6.3814   6.3814
Dividends, preferred stock | $ $ 74 $ 74  
Series Y - 5.625% Non-Cumulative Perpetual Class A Preferred Stock [Member]      
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]      
Preferred stock, shares authorized and designated 27,600   27,600
Preferred stock, shares issued and outstanding 27,600   27,600
Preferred stock, liquidation preference, value | $ $ 690   $ 690
Preferred stock, carrying value | $ $ 690   $ 690
Preferred stock, dividend rate (percent) 5.625%   5.625%
Series Z - 4.75% Non-Cumulative Perpetual Class A Preferred Stock [Member]      
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]      
Preferred stock, shares authorized and designated 80,500   80,500
Preferred stock, shares issued and outstanding 80,500   80,500
Preferred stock, liquidation preference, value | $ $ 2,013   $ 2,013
Preferred stock, carrying value | $ $ 2,013   $ 2,013
Preferred stock, dividend rate (percent) 4.75%   4.75%
Series AA - 4.70% Non-Cumulative Perpetual Class A Preferred Stock [Member]      
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]      
Preferred stock, shares authorized and designated 46,800   46,800
Preferred stock, shares issued and outstanding 46,800   46,800
Preferred stock, liquidation preference, value | $ $ 1,170   $ 1,170
Preferred stock, carrying value | $ $ 1,170   $ 1,170
Preferred stock, dividend rate (percent) 4.70%   4.70%
Series BB - 3.90% Fixed-Reset Non-Cumulative Perpetual Class A Preferred Stock [Member]      
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]      
Preferred stock, shares authorized and designated 0   140,400
Preferred stock, shares issued and outstanding 0   140,400
Preferred stock, liquidation preference, value | $ $ 0   $ 3,510
Preferred stock, carrying value | $ $ 0   $ 3,510
Preferred stock, dividend rate (percent) 3.90%   3.90%
Series CC - 4.375% Non-Cumulative Perpetual Class A Preferred Stock [Member]      
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]      
Preferred stock, shares authorized and designated 46,000   46,000
Preferred stock, shares issued and outstanding 42,000   42,000
Preferred stock, liquidation preference, value | $ $ 1,050   $ 1,050
Preferred stock, carrying value | $ $ 1,050   $ 1,050
Preferred stock, dividend rate (percent) 4.375%   4.375%
Series DD - 4.25% Non-Cumulative Perpetual Class A Preferred Stock [Member]      
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]      
Preferred stock, shares authorized and designated 50,000   50,000
Preferred stock, shares issued and outstanding 50,000   50,000
Preferred stock, liquidation preference, value | $ $ 1,250   $ 1,250
Preferred stock, carrying value | $ $ 1,250   $ 1,250
Preferred stock, dividend rate (percent) 4.25%   4.25%
Series EE - 7.625% Fixed-Reset-Non-Cumulative Perpetual Class A Preferred Stock [Member]      
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]      
Preferred stock, shares authorized and designated 69,000   69,000
Preferred stock, shares issued and outstanding 69,000   69,000
Preferred stock, liquidation preference, value | $ $ 1,725   $ 1,725
Preferred stock, carrying value | $ $ 1,725   $ 1,725
Preferred stock, dividend rate (percent) 7.625%   7.625%
Series FF - 6.85% Fixed-Reset-Non-Cumulative Perpetual Class A Preferred Stock [Member]      
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]      
Preferred stock, shares authorized and designated 80,000   80,000
Preferred stock, shares issued and outstanding 80,000   80,000
Preferred stock, liquidation preference, value | $ $ 2,000   $ 2,000
Preferred stock, carrying value | $ $ 2,000   $ 2,000
Preferred stock, dividend rate (percent) 6.85%   6.85%
Series GG - 6.125% Fixed-Reset-Non-Cumulative Perpetual Class A Preferred Stock [Member]      
Preferred Stock, Number of Shares, Par Value and Other Disclosure [Abstract]      
Preferred stock, shares authorized and designated 90,000   0
Preferred stock, shares issued and outstanding 90,000   0
Preferred stock, liquidation preference, value | $ $ 2,250   $ 0
Preferred stock, carrying value | $ $ 2,250   $ 0
Preferred stock, dividend rate (percent) 6.125%