Corporate Investments and Funds Held For Clients (Classification Of Corporate Investments On The Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jun. 30, 2017	Mar. 31, 2017
Corporate Investments And Funds Held For Clients [Abstract]
Cash and cash equivalents	$ 2,293.6	$ 2,780.4	$ 2,995.5
Short-term marketable securities	0.0	3.2
Long-term marketable securities	7.3	7.6
Total corporate investments	$ 2,300.9	$ 2,791.2