Fair Value Measurements (Schedule Of Assets Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions	Jun. 30, 2011	Jun. 30, 2010
Total available-for-sale securities	$ 16,927.5	$ 15,517.0
U.S. Treasury And Direct Obligations Of U.S. Government Agencies [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Total available-for-sale securities	6,759.1	5,911.4
U.S. Treasury And Direct Obligations Of U.S. Government Agencies [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Total available-for-sale securities
U.S. Treasury And Direct Obligations Of U.S. Government Agencies [Member] \| Total [Member]
Total available-for-sale securities	6,759.1	5,911.4
Corporate Bonds [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Total available-for-sale securities	6,126.6	5,332.9
Corporate Bonds [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Total available-for-sale securities
Corporate Bonds [Member] \| Total [Member]
Total available-for-sale securities	6,126.6	5,332.9
Asset-Backed Securities [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Total available-for-sale securities	447.8	968.9
Asset-Backed Securities [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Total available-for-sale securities
Asset-Backed Securities [Member] \| Total [Member]
Total available-for-sale securities	447.8	968.9
Commercial Mortgage-Backed Securities [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Total available-for-sale securities	492.5	707.4
Commercial Mortgage-Backed Securities [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Total available-for-sale securities
Commercial Mortgage-Backed Securities [Member] \| Total [Member]
Total available-for-sale securities	492.5	707.4
Municipal Bonds [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Total available-for-sale securities	516.2	469.5
Municipal Bonds [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Total available-for-sale securities
Municipal Bonds [Member] \| Total [Member]
Total available-for-sale securities	516.2	469.5
Canadian Government Obligations And Canadian Government Agency Obligations [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Total available-for-sale securities	1,101.5	1,032.5
Canadian Government Obligations And Canadian Government Agency Obligations [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Total available-for-sale securities
Canadian Government Obligations And Canadian Government Agency Obligations [Member] \| Total [Member]
Total available-for-sale securities	1,101.5	1,032.5
Other Securities [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Total available-for-sale securities	20.1	8.0
Other Securities [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Total available-for-sale securities	1,463.7	1,086.4
Other Securities [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Total available-for-sale securities
Other Securities [Member] \| Total [Member]
Total available-for-sale securities	1,483.8	1,094.4
Corporate Investments [Member]
Total available-for-sale securities	134.3	132.2
Funds Held For Clients [Member]
Total available-for-sale securities	16,793.2	15,384.8
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Total available-for-sale securities	20.1	8.0
Significant Other Observable Inputs (Level 2) [Member]
Total available-for-sale securities	16,907.4	15,509.0
Significant Unobservable Inputs (Level 3) [Member]
Total available-for-sale securities
Total [Member]
Total available-for-sale securities	$ 16,927.5	$ 15,517.0

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.

+ References+ Details