Corporate Investments and Funds Held For Clients (Schedule Of Investment Of Funds Held For Clients) (Details) - USD ($) $ in Millions	Sep. 30, 2019		Jun. 30, 2019	Sep. 30, 2018	[1]
Corporate Investments And Funds Held For Clients [Abstract]
Restricted cash and cash equivalents held to satisfy client funds obligations	$ 868.3	[1]	$ 4,847.0	$ 2,918.0
Total funds held for clients	$ 21,393.2		$ 29,434.2

[1] See Note 6 for a reconciliation of restricted cash and restricted cash equivalents in funds held for clients on the Consolidated Balance Sheets.