Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	$ 392.0	$ 214.7
Adjustments to Reconcile Net Income to Net Cash Used in Operating Activities
Investment Security Losses/(Gains)	0.0	189.4
Amortization and Accretion of Securities and Unearned Income, net	(13.9)	(7.7)
Provision for Credit Losses	1.0	(8.5)
Depreciation and Amortization	190.7	170.3
Pension Plan Contributions	(137.9)	(208.0)
Change in Receivables	(206.0)	(173.4)
Change in Interest Payable	44.0	56.4
Change in Collateral With Derivative Counterparties, net	2,335.0	(1,118.0)
Other Operating Activities, net	144.9	(567.8)
Net Cash Provided by / (Used in) Operating Activities	2,749.8	(1,452.6)
CASH FLOWS FROM INVESTING ACTIVITIES
Change in Federal Funds Sold and Securities Purchased under Agreements to Resell	327.9	251.9
Change in Interest-Bearing Deposits with Banks	305.3	523.3
Net Change in Federal Reserve and Other Central Bank Deposits	(13,621.9)	(6,267.8)
Purchases of Held to Maturity Debt Securities	(6,126.8)	(6,134.3)
Proceeds from the Maturity and Redemption of Held to Maturity Debt Securities	7,927.8	8,606.3
Purchases of Available for Sale Debt Securities	(2,495.6)	(5,537.5)
Proceeds from the Maturity and Sales of Available for Sale Debt Securities	1,241.3	2,894.5
Change in Loans	2,576.3	253.7
Purchases of Buildings and Equipment	(12.4)	(14.3)
Purchases and Development of Computer Software	(171.1)	(113.5)
Change in Client Security Settlement Receivables	(304.0)	90.7
Proceeds from the sale of Visa Shares	3.9	0.0
Other Investing Activities, net	63.9	653.6
Net Cash (Used in) Investing Activities	(10,285.4)	(4,793.4)
CASH FLOWS FROM FINANCING ACTIVITIES
Change in Deposits	7,171.9	7,982.9
Change in Federal Funds Purchased	218.1	(445.0)
Change in Securities Sold under Agreements to Repurchase	(126.4)	(273.3)
Change in Short-Term Other Borrowings	8.2	(30.5)
Treasury Stock Purchased	(287.2)	(132.0)
Net Proceeds from Stock Options	4.5	4.1
Cash Dividends Paid on Common Stock	(146.1)	(153.6)
Cash Dividends Paid on Preferred Stock	(16.2)	(16.2)
Other Financing Activities, net	(2.5)	(0.4)
Net Cash Provided by Financing Activities	6,824.3	6,936.0
Effect of Foreign Currency Exchange Rates on Cash	402.8	(172.8)
Change in Cash and Due from Banks	(308.5)	517.2
Cash and Due from Banks at Beginning of Period	4,677.2	4,791.5
Cash and Due from Banks at End of Period	4,368.7	5,308.7
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Interest Paid	1,524.4	1,857.0
Income Taxes Paid	$ 52.3	$ 39.3