Revenue from Contracts with Clients (Revenue Disaggregation) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Foreign Exchange Trading Income	$ 78.9	$ 49.9	$ 157.4	$ 98.0
Treasury Management Fees	13.5	14.9	27.5	29.6
Security Commissions and Trading Income	26.1	24.1	53.3	44.6
Other operating income	31.4		66.2
Investment Security Losses, net	0.0	(0.4)	(0.2)	(0.7)
Total Other Noninterest Income	149.9		304.2
Noninterest Income	1,092.8	979.7	2,184.8	1,910.6
Custody and Fund Administration
Disaggregation of Revenue [Line Items]
Revenue from contract with client	399.1		795.0
Investment Management and Advisory
Disaggregation of Revenue [Line Items]
Revenue from contract with client	465.0		930.6
Securities Lending
Disaggregation of Revenue [Line Items]
Revenue from contract with client	30.4		56.6
Other
Disaggregation of Revenue [Line Items]
Revenue from contract with client	48.4		98.4
Total Trust, Investment and Other Servicing Fees
Disaggregation of Revenue [Line Items]
Revenue from contract with client	942.9	$ 848.2	1,880.6	$ 1,656.4
Other Operating Income
Disaggregation of Revenue [Line Items]
Revenue from contract with client	$ 11.6		$ 22.9

Other Noninterest Income

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- Definition

Revenues earned for buying and selling securities on behalf of clients and other fees including fees earned for transitioning assets between investment firms, fees earned for buying and selling interest rate protection products, and other fees.

+ References

No definition available.

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Fees earned from treasury management activities including disbursements and receivables management, funds transfer, and online reporting.

+ References

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Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
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This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

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The total amount of noninterest income which may be derived from: (1) fees and commissions; (2) premiums earned; (3) insurance policy charges; (4) the sale or disposal of assets; and (5) other sources not otherwise specified.

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The total amount of other operating income, the components of which are not separately disclosed on the income statement, from items that are associated with the entity's normal revenue producing operation.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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