Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income		$ 1,362	$ 1,603
Preferred stock dividends and other		(111)	(70)
Net Income Available to Common Stockholders		$ 1,251	$ 1,533
Weighted-average common shares outstanding - basic (in shares)		1,825	1,834
Basic earnings per share (in USD per share)	[1]	$ 0.69	$ 0.84
Weighted-average common shares outstanding - diluted (in shares)		1,831	1,842
Diluted earnings per share (in USD per share)	[1]	$ 0.68	$ 0.83
Antidilutive stock options and restricted stock awards excluded from the calculation of diluted EPS (in shares)		18	16
Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income		$ 1,324	$ 1,559
Preferred stock dividends and other		(108)	(68)
Net Income Available to Common Stockholders		$ 1,216	$ 1,491
Weighted-average common shares outstanding - basic (in shares)		1,774	1,783
Basic earnings per share (in USD per share)		$ 0.69	$ 0.84
Reallocation of net income available to common stockholders as a result of conversion of nonvoting to voting shares		$ 35	$ 42
Allocation of net income available to common stockholders:		$ 1,251	$ 1,533
Conversion of nonvoting shares to voting shares (in shares)		51	51
Common stock equivalent shares related to stock incentive plans (in shares)		6	8
Weighted-average common shares outstanding - diluted (in shares)		1,831	1,842
Diluted earnings per share (in USD per share)		$ 0.68	$ 0.83
Nonvoting Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income		$ 38	$ 44
Preferred stock dividends and other		(3)	(2)
Net Income Available to Common Stockholders		$ 35	$ 42
Weighted-average common shares outstanding - basic (in shares)		51	51
Basic earnings per share (in USD per share)		$ 0.69	$ 0.84
Reallocation of net income available to common stockholders as a result of conversion of nonvoting to voting shares		$ 0	$ 0
Allocation of net income available to common stockholders:		$ 35	$ 42
Conversion of nonvoting shares to voting shares (in shares)		0	0
Common stock equivalent shares related to stock incentive plans (in shares)		0	0
Weighted-average common shares outstanding - diluted (in shares)		51	51
Diluted earnings per share (in USD per share)		$ 0.68	$ 0.83

[1] The Company has voting and nonvoting common stock outstanding. As the participation rights, including dividend and liquidation rights, are identical between the voting and nonvoting stock classes, basic and diluted earnings per share are the same for each class. See Note 16 for additional information.