Corporate Investments And Funds Held For Clients (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Sep. 30, 2012	Jun. 30, 2012
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	$ 18,417.0	$ 18,093.4
Earliest non-callable debt maturity date	October 2012
Latest non-callable debt maturity date	August 2022
Length of shortest cash flow of residential mortgages used as collateral for companies mortgage backed securities (in years)	15 years
Length of longest cash flow of residential mortgages used as collateral for company's mortgage backed securities (in years)	30 years
Client funds obligations	19,701.3	20,856.2
Client funds investments with original maturities	90 days or less
Percentage of the available-for-sale securities were rated AAA or AA	84.00%
Federal Home Loan Banks [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	4,100.2	4,189.1
Federal Farm Credit Banks [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	1,324.2	1,134.1
Federal National Mortgage Association ("Fannie Mae") [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	393.3	428.6
Federal Home Loan Mortgage Corporation ("Freddie Mac") [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	281.2	384.6
Fixed Rate Credit Card [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	415.3	323.0
Rate Reduction [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	116.4	140.0
Asset-Backed Auto Loan Receivables [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	84.7	85.1
Sovereign Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	412.4	405.0
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	126.8	135.3
Supranational Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	440.9	427.7
Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	$ 251.0	$ 282.3

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

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