Consolidated Statement of Condition (Parenthetical) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Assets, Current [Abstract]
Debt securities, AFS, allowance	$ 0	$ 2,000,000
Debt securities, HTM, allowance	1,000,000	0
Allowance for credit losses	135,000,000	97,000,000
Investment securities held-to-maturity	51,503,000,000	57,913,000,000
Accumulated depreciation	$ 6,062,000,000	$ 5,745,000,000
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, no par value (in USD per share)	$ 0
Preferred stock authorized (in shares)	3,500,000
Common stock, par value (in USD per share)	$ 1
Common stock, shares authorized (in shares)	750,000,000
Common stock, shares issued (in shares)	503,879,642	503,879,642
Common stock, shares outstanding (in shares)	301,944,043	349,024,167
Treasury stock, shares (in shares)	201,935,599	154,855,475
Series D Preferred Stock
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares issued (in shares)	7,500
Preferred stock, shares outstanding (in shares)	7,500
Series F Preferred Stock
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares issued (in shares)	2,500
Preferred stock, shares outstanding (in shares)	2,500
Series G Preferred Stock
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares issued (in shares)	5,000
Preferred stock, shares outstanding (in shares)	5,000
Series H Preferred Stock
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares issued (in shares)	5,000
Preferred stock, shares outstanding (in shares)	5,000