Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	$ 673.9	$ 736.5
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Investment Security (Losses) Gains, net	(0.1)	0.5
Amortization and Accretion of Securities and Unearned Income, net	39.8	37.6
Provision for Credit Losses	127.0	(6.5)
Depreciation on Buildings and Equipment	57.6	49.7
Amortization of Computer Software	182.7	168.3
Amortization of Intangibles	8.3	8.3
Pension Plan Contributions	(10.6)	(3.0)
Change in Receivables	(39.4)	(470.3)
Change in Interest Payable	(16.1)	(5.3)
Change in Collateral With Derivative Counterparties, net	(867.4)	357.3
Other Operating Activities, net	342.7	(494.6)
Net Cash Provided by Operating Activities	498.4	378.5
CASH FLOWS FROM INVESTING ACTIVITIES
Net Change in Federal Funds Sold and Securities Purchased under Agreements to Resell	(763.0)	509.4
Change in Interest-Bearing Deposits with Banks	2,057.8	76.7
Net Change in Federal Reserve and Other Central Bank Deposits	(8,444.3)	2,492.8
Purchases of Debt Securities – Held to Maturity	(15,952.0)	(6,321.1)
Proceeds from Maturity and Redemption of Debt Securities – Held to Maturity	12,887.2	10,272.9
Purchases of Debt Securities – Available for Sale	(5,186.5)	(4,361.7)
Proceeds from Sale, Maturity and Redemption of Debt Securities – Available for Sale	4,556.7	3,772.5
Change in Loans and Leases	(2,350.3)	1,513.3
Purchases of Buildings and Equipment	(76.6)	(27.7)
Purchases and Development of Computer Software	(187.8)	(208.8)
Change in Client Security Settlement Receivables	(1,159.2)	331.2
Bank-Owned Life Insurance Policy Premiums	0.0	(1,000.0)
Other Investing Activities, net	326.7	281.8
Net Cash (Used in) Provided by Investing Activities	(14,291.3)	7,331.3
CASH FLOWS FROM FINANCING ACTIVITIES
Change in Deposits	13,425.2	(4,303.7)
Change In Federal Funds Purchased	161.8	(2,226.1)
Change in Securities Sold under Agreements to Repurchase	(453.2)	(43.8)
Change in Short-Term Other Borrowings	747.7	(145.2)
Redemption of Preferred Stock - Series C	(400.0)	0.0
Proceeds from Senior Notes	993.2	498.0
Treasury Stock Purchased	(297.0)	(528.6)
Net Proceeds from Stock Options	10.6	9.1
Cash Dividends Paid on Common Stock	(293.0)	(251.9)
Cash Dividends Paid on Preferred Stock	(25.0)	(23.2)
Other Financing Activities, net	0.3	0.0
Net Cash Provided by (Used in) Financing Activities	13,870.6	(7,015.4)
Effect of Foreign Currency Exchange Rates on Cash	(74.7)	72.3
Change in Cash and Due from Banks	3.0	766.7
Cash and Due from Banks at Beginning of Year	4,459.2	4,581.6
Cash and Due from Banks at End of Year	4,462.2	5,348.3
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Interest Paid	174.7	469.2
Income Taxes Paid	189.7	233.0
Transfers from Loans to OREO	0.2	2.5
Transfers from Debt Securities Available for Sale to Debt Securities Held to Maturity	$ 301.5	$ 0.0