Corporate Investments and Funds Held For Clients (Schedule Of Investment Of Funds Held For Clients) (Details) - USD ($) $ in Millions	Dec. 31, 2019		Jun. 30, 2019	Dec. 31, 2018	[1]
Debt Securities, Available-for-sale [Line Items]
Restricted cash and cash equivalents held to satisfy client funds obligations	$ 11,814.7	[1]	$ 4,847.0	$ 2,698.4
Total funds held for clients	36,608.6		29,434.2
Current
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, restricted	5,241.3		5,013.9
Non-current
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, restricted	$ 19,552.6		$ 19,573.3

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