Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	$ 1,556.4	$ 1,199.0	$ 1,032.5
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Investment Security Losses, net	1.0	1.6	3.2
Amortization and Accretion of Securities and Unearned Income, net	95.9	105.0	100.9
Provision for Credit Losses	(14.5)	(28.0)	(26.0)
Depreciation on Buildings and Equipment	108.6	101.2	89.2
Amortization of Computer Software	334.9	309.1	275.3
Amortization of Intangibles	17.4	11.4	8.8
Change in Accrued Income Taxes	(130.0)	36.2	(129.0)
Pension Plan Contributions	(74.5)	(14.5)	(12.8)
Deferred Income Tax Provision	10.5	(76.1)	(175.8)
Change in Receivables	(197.0)	(119.3)	(129.2)
Change in Interest Payable	28.5	10.7	(0.1)
Change in Collateral With Derivative Counterparties, net	(699.6)	486.2	(180.4)
Other Operating Activities, net	729.9	(302.1)	653.4
Net Cash Provided by Operating Activities	1,767.5	1,720.4	1,510.0
CASH FLOWS FROM INVESTING ACTIVITIES
Net Change in Federal Funds Sold and Securities Purchased under Agreements to Resell	105.7	678.9	(372.9)
Change in Interest-Bearing Deposits with Banks	1,073.8	(467.7)	1,906.1
Net Change in Federal Reserve and Other Central Bank Deposits	9,679.6	(12,748.7)	(4,124.2)
Purchases of Debt Securities – Held to Maturity	(21,463.1)	(11,955.2)	(8,573.2)
Proceeds from Maturity and Redemption of Debt Securities – Held to Maturity	20,036.7	9,924.8	4,026.5
Purchases of Debt Securities – Available for Sale	(12,596.9)	(9,780.0)	(14,741.9)
Proceeds from Sale, Maturity and Redemption of Debt Securities – Available for Sale	8,958.7	10,103.4	11,317.3
Change in Loans and Leases	66.1	1,451.0	(471.0)
Purchases of Buildings and Equipment	(97.6)	(91.6)	(111.3)
Purchases and Development of Computer Software	(408.4)	(381.2)	(362.1)
Change in Client Security Settlement Receivables	(49.7)	(592.6)	1,105.0
Acquisition of a Business, Net of Cash Received	(104.2)	(188.5)	(16.9)
Other Investing Activities, net	(873.6)	25.8	226.5
Net Cash Provided by (Used in) Investing Activities	4,327.1	(14,021.6)	(10,192.1)
CASH FLOWS FROM FINANCING ACTIVITIES
Change in Deposits	(6,163.2)	8,523.6	6,737.4
Change in Federal Funds Purchased	308.1	2,081.2	(146.7)
Change in Securities Sold under Agreements to Repurchase	(665.2)	360.5	(72.9)
Change in Short-Term Other Borrowings	1,860.9	967.7	1,073.5
Proceeds from Senior Notes and Long-Term Debt	497.9	350.0	0.0
Repayments of Senior Notes and Long-Term Debt	(314.3)	(208.7)	(6.7)
Proceeds from Issuance of Preferred Stock - Series D	0.0	0.0	493.5
Treasury Stock Purchased	(924.3)	(523.1)	(411.1)
Net Proceeds from Stock Options	32.6	108.0	233.8
Cash Dividends Paid on Common Stock	(405.4)	(356.8)	(333.0)
Cash Dividends Paid on Preferred Stock	(46.4)	(49.8)	(23.4)
Other Financing Activities, net	1.1	0.1	(7.5)
Net Cash (Used In) Provided by Financing Activities	(5,818.2)	11,252.7	7,536.9
Effect of Foreign Currency Exchange Rates on Cash	(212.9)	234.6	58.7
Change in Cash and Due from Banks	63.5	(813.9)	(1,086.5)
Cash and Due from Banks at Beginning of Year	4,518.1	5,332.0	6,418.5
Cash and Due from Banks at End of Year	4,581.6	4,518.1	5,332.0
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Interest Paid	670.2	328.8	181.6
Income Taxes Paid	493.5	441.2	754.2
Transfers from Loans to OREO	$ 11.4	$ 8.2	$ 14.2