Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	$ 973.8	$ 811.8	$ 731.3
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Investment Security Losses (Gains), net	0.3	4.3	1.5
Amortization and Accretion of Securities and Unearned Income, net	53.3	34.8	44.7
Provision for Credit Losses	(43.0)	6.0	20.0
Depreciation on Buildings and Equipment	90.4	90.6	92.3
Amortization of Intangibles	10.9	19.5	21.1
Change in Accrued Income Taxes	206.8	55.2	(31.5)
Pension Plan Contributions	(21.1)	(18.7)	(20.7)
Deferred Income Tax Provision	(146.2)	(36.4)	66.6
Change in Receivables	(16.2)	20.9	(206.2)
Change in Interest Payable	(8.2)	(4.5)	(11.2)
Change in Collateral With Derivative Counterparties, net	801.4	(359.2)	(250.6)
Other Operating Activities, net	(318.1)	86.1	176.9
Net Cash Provided by Operating Activities	1,834.4	936.0	839.3
CASH FLOWS FROM INVESTING ACTIVITIES
Net Change in Federal Funds Sold and Securities Purchased under Agreements to Resell	(549.8)	(533.1)	(468.8)
Change in Interest-Bearing Deposits with Banks	(144.9)	3,297.2	(782.1)
Net Change in Federal Reserve Deposits	987.8	(4,474.8)	(5,292.1)
Purchases of Securities – Held to Maturity	(8,075.5)	(7,138.7)	(5,715.5)
Proceeds from Maturity and Redemption of Securities – Held to Maturity	6,628.3	4,907.7	5,853.9
Purchases of Securities – Available for Sale	(11,490.3)	(12,668.0)	(8,168.0)
Proceeds from Sale, Maturity and Redemption of Securities – Available for Sale	8,576.1	11,476.6	8,456.4
Change in Loans and Leases	(1,581.0)	(2,288.3)	17.8
Purchases of Buildings and Equipment	(98.5)	(81.9)	(91.9)
Purchases and Development of Computer Software	(335.0)	(327.6)	(293.0)
Change in Client Security Settlement Receivables	(605.0)	(224.1)	690.6
Other Investing Activities, net	(212.9)	(157.4)	109.4
Net Cash Used in Investing Activities	(6,900.7)	(8,212.4)	(5,683.3)
CASH FLOWS FROM FINANCING ACTIVITIES
Change in Deposits	8,105.7	8,487.7	2,938.9
Change in Federal Funds Purchased	(581.4)	(32.2)	184.9
Change in Securities Sold under Agreements to Repurchase	(338.5)	(32.2)	217.5
Change in Short-Term Other Borrowings	2,312.8	(164.3)	1,258.8
Proceeds from Senior Notes and Long-Term Debt	0.0	0.0	750.0
Repayments of Senior Notes and Long-Term Debt	(231.0)	(640.0)	(804.4)
Contingent Consideration Liability Payment	0.0	(55.3)	0.0
Proceeds from Issuance of Preferred Stock – Series C	0.0	388.5	0.0
Treasury Stock Purchased	(496.9)	(480.7)	(309.7)
Net Proceeds from Stock Options	94.0	127.5	146.2
Cash Dividends Paid on Common Stock	(321.4)	(302.9)	(220.6)
Cash Dividends Paid on Preferred Stock	(27.0)	0.0	0.0
Other Financing Activities, net	17.8	(222.4)	226.7
Net Cash Provided by Financing Activities	8,534.1	7,073.7	4,388.3
Effect of Foreign Currency Exchange Rates on Cash	(73.8)	90.9	(134.6)
Increase (Decrease) in Cash and Due from Banks	3,394.0	(111.8)	(590.3)
Cash and Due from Banks at Beginning of Year	3,050.6	3,162.4	3,752.7
Cash and Due from Banks at End of Year	6,444.6	3,050.6	3,162.4
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Interest Paid	161.6	186.5	231.9
Income Taxes Paid	390.0	279.2	262.6
Transfers from Loans to OREO	13.0	21.4	24.7
Computer Software
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Amortization of Intangibles	250.3	225.6	205.1
Other Intangible Assets
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Amortization of Intangibles	$ 10.9	$ 19.5	$ 21.1