Corporate Investments and Funds Held For Clients (Classification Of Corporate Investments On The Consolidated Balance Sheets) (Details) - USD ($) $ in Millions		Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018
Corporate Investments And Funds Held For Clients [Abstract]
Cash and cash equivalents		$ 1,826.2	$ 2,170.0	$ 2,293.6
Short-term marketable securities	[1]	7.3	3.3
Long-term marketable securities	[2]	3.2	7.2
Total corporate investments		$ 1,836.7	$ 2,180.5

[1] (a) - Short-term marketable securities are included within Other current assets on the Consolidated Balance Sheets.

[2] (b) - Long-term marketable securities are included within Other assets on the Consolidated Balance Sheets.