Corporate Investments And Funds Held For Clients (Classification Of Corporate Investments On The Consolidated Balance Sheets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Corporate Investments And Funds Held For Clients [Abstract]
Cash and cash equivalents	$ 1,390.9	[1]	$ 1,548.1	$ 1,331.3	$ 1,389.4
Short-term marketable securities	43.9	[1]	30.4
Long-term marketable securities	82.4		86.9
Total corporate investments	$ 1,517.2		$ 1,665.4

[1] As of December 31, 2012, $13.4 million of short-term marketable securities and $0.1 million of cash and cash equivalents have been pledged as collateral under the Company's reverse repurchase agreements (see Note 11).