Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	$ 389.3	$ 375.1
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Investment Security (Losses) Gains, net	0.0	0.0
Amortization and Accretion of Securities and Unearned Income, net	21.7	26.1
Provision for Credit Losses	2.0	(30.0)
Depreciation and Amortization	130.9	125.4
Pension Plan Contributions	(20.7)	(6.7)
Change in Receivables	285.4	(66.7)
Change in Interest Payable	12.0	7.3
Change in Collateral With Derivative Counterparties, net	(505.7)	(824.2)
Other Operating Activities, net	432.0	462.0
Net Cash Provided by Operating Activities	746.9	68.3
CASH FLOWS FROM INVESTING ACTIVITIES
Change in Federal Funds Sold	0.0	(0.1)
Change in Securities Purchased under Agreements to Resell	(336.2)	477.9
Change in Interest-Bearing Deposits with Banks	(843.9)	(772.6)
Net Change in Federal Reserve and Other Central Bank Deposits	8,497.2	8,369.3
Purchases of Held to Maturity Debt Securities	(11,916.4)	(16,047.6)
Proceeds from Maturity and Redemption of Held to Maturity Debt Securities	13,983.4	16,125.8
Purchases of Available for Sale Debt Securities	(1,784.8)	(3,631.9)
Proceeds from Maturity and Redemption of Available for Sale Debt Securities	1,821.5	2,214.9
Change in Loans and Leases	1,233.1	(592.4)
Purchases of Buildings and Equipment	(25.8)	(10.7)
Purchases and Development of Computer Software	(123.2)	(94.8)
Change in Client Security Settlement Receivables	(250.3)	(810.4)
Other Investing Activities, net	71.0	(93.7)
Net Cash Provided by Investing Activities	10,325.6	5,133.7
CASH FLOWS FROM FINANCING ACTIVITIES
Change in Deposits	(9,862.9)	(5,844.1)
Change in Federal Funds Purchased	0.0	(260.0)
Change in Securities Sold under Agreements to Repurchase	(202.2)	55.8
Change in Short-Term Other Borrowings	(70.4)	1,420.3
Treasury Stock Purchased	(33.8)	(135.6)
Net Proceeds from Stock Options	2.6	8.7
Cash Dividends Paid on Common Stock	(145.5)	(145.9)
Cash Dividends Paid on Preferred Stock	(4.7)	(4.7)
Other Financing Activities, net	0.3	(0.1)
Net Cash Used in Financing Activities	(10,316.6)	(4,905.6)
Effect of Foreign Currency Exchange Rates on Cash	(29.5)	(101.5)
Change in Cash and Due from Banks	726.4	194.9
Cash and Due from Banks at Beginning of Period	3,056.8	4,389.5
Cash and Due from Banks at End of Period	3,783.2	4,584.4
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Interest (Received) Paid	(9.7)	2.2
Income Taxes Paid	47.2	30.8
Transfers from Loans to OREO	$ 0.0	$ 3.3