Consolidated Statements of Cash Flows (Unaudited - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash Flows from Operating Activities:
Net Income	$ 381.6	$ 276.1
Adjustments to Reconcile Net Income to Net Cash (Used in) Provided by Operating Activities:
Investment Security Losses, net	0.2	0.3
Amortization and Accretion of Securities and Unearned Income, net	35.6	18.9
Provision for Credit Losses	(3.0)	(1.0)
Depreciation on Buildings and Equipment	27.8	23.3
Pension Plan Contributions	(71.9)	(11.5)
Change in Receivables	(79.7)	(5.6)
Change in Interest Payable	5.7	5.9
Change in Collateral With Derivative Counterparties, net	(619.8)	572.5
Other Operating Activities, net	(242.4)	(172.2)
Net Cash (Used in) Provided by Operating Activities	(477.8)	784.7
Cash Flows from Investing Activities:
Net Change in Federal Funds Sold and Securities Purchased under Agreements to Resell	(211.9)	52.7
Change in Interest-Bearing Deposits with Banks	660.2	(327.8)
Net Change in Federal Reserve and Other Central Bank Deposits	11,533.0	767.1
Purchases of Debt Securities — Held to Maturity	(5,511.6)	(2,284.1)
Proceeds from Maturity and Redemption of Debt Securities — Held to Maturity	4,678.4	2,450.9
Purchases of Debt Securities — Available for Sale	(2,725.3)	(2,633.6)
Proceeds from Sale, Maturity and Redemption of Debt Securities — Available for Sale	2,044.4	3,235.9
Change in Loans and Leases	491.2	153.0
Purchases of Buildings and Equipment	(6.0)	(14.3)
Purchases and Development of Computer Software	(79.8)	(79.9)
Change in Client Security Settlement Receivables	1,058.2	(519.8)
Other Investing Activities, net	(774.6)	226.4
Net Cash Provided by Investing Activities	11,156.2	1,026.5
Cash Flows from Financing Activities:
Change in Deposits	(7,841.1)	(1,671.8)
Change in Federal Funds Purchased	(1,953.3)	164.7
Change in Securities Sold under Agreements to Repurchase	(23.8)	(40.4)
Change in Short-Term Other Borrowings	997.7	(1,030.6)
Repayments of Senior Notes and Long-Term Debt	(1.7)	(3.8)
Treasury Stock Purchased	(263.2)	(70.1)
Net Proceeds from Stock Options	19.1	37.2
Cash Dividends Paid on Common Stock	(95.0)	(86.9)
Cash Dividends Paid on Preferred Stock	(5.9)	(5.9)
Net Cash Used in Financing Activities	(9,167.2)	(2,707.6)
Effect of Foreign Currency Exchange Rates on Cash	52.1	213.6
Change in Cash and Due from Banks	1,563.3	(682.8)
Cash and Due from Banks at Beginning of Year	4,518.1	5,332.0
Cash and Due from Banks at End of Period	6,081.4	4,649.2
Supplemental Disclosures of Cash Flow Information:
Interest Paid	116.0	50.8
Income Taxes Paid	29.7	43.5
Transfers from Loans to OREO	1.1	2.3
Computer Software
Adjustments to Reconcile Net Income to Net Cash (Used in) Provided by Operating Activities:
Amortization of Intangibles	83.6	75.6
Other Intangible Assets
Adjustments to Reconcile Net Income to Net Cash (Used in) Provided by Operating Activities:
Amortization of Intangibles	$ 4.5	$ 2.4