Corporate Investments and Funds Held For Clients (Expected Maturities Of Available-For-Sale Securities) (Details) - USD ($) $ in Millions	Sep. 30, 2021	Jun. 30, 2021
Corporate Investments And Funds Held For Clients [Abstract]
One year or less	$ 4,118.8
One year to two years	3,657.9
Two years to three years	2,933.0
Three years to four years	4,626.3
After four years	9,956.7
Total available-for-sale securities	$ 25,292.7	$ 24,371.7