Consolidated Statement of Condition (Parenthetical) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Assets, Current [Abstract]
Allowance for credit losses on available-for-sale securities	$ 2,000,000	$ 2,000,000
Allowance for credit losses on HTM investment securities	0	0
Investment securities held-to-maturity	59,139,000,000	57,913,000,000
Allowance for credit losses on loans	115,000,000	97,000,000
Accumulated depreciation	5,918,000,000	5,745,000,000
Stockholders' Equity Attributable to Parent [Abstract]
Interest-bearing deposits with banks, allowance for credit loss	$ 29,000,000	$ 0
Preferred stock, no par value (in USD per share)	$ 0	$ 0
Preferred stock authorized (in shares)	3,500,000	3,500,000
Common stock, par value (usd per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	750,000,000	750,000,000
Common stock, shares issued (in shares)	503,879,642	503,879,642
Common stock, shares outstanding (in shares)	336,461,072	349,024,167
Treasury stock (shares)	167,418,570	154,855,475
Series D Preferred Stock
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares issued (in shares)	7,500	7,500
Preferred stock, shares outstanding (in shares)	7,500	7,500
Series F Preferred Stock
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares issued (in shares)	2,500	2,500
Preferred stock, shares outstanding (in shares)	2,500	2,500
Series G Preferred Stock
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares issued (in shares)	5,000	5,000
Preferred stock, shares outstanding (in shares)	5,000	5,000
Series H Preferred Stock
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares issued (in shares)	5,000	5,000
Preferred stock, shares outstanding (in shares)	5,000	5,000