Corporate Investments And Funds Held For Clients (Classification Of Corporate Investments On The Consolidated Balance Sheets) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Jun. 30, 2012		Sep. 30, 2011	Jun. 30, 2011
Corporate Investments And Funds Held For Clients [Abstract]
Cash and cash equivalents	$ 1,117.4	[1]	$ 1,548.1	[1]	$ 1,248.9	$ 1,389.4
Short-term marketable securities	35.7		30.4
Long-term marketable securities	522.4	[1]	86.9	[1]
Total corporate investments	$ 1,675.5		$ 1,665.4

[1] As of September 30, 2012, $439.4 million of long-term marketable securities and $3.3 million of cash and cash equivalents have been pledged as collateral under the Company's reverse repurchase agreements (see Note 12).