Corporate Investments And Funds Held For Clients (Expected Maturities Of Available-For-Sale Securities) (Details) $ in Millions	Sep. 30, 2015 USD ($)
Corporate Investments And Funds Held For Clients [Abstract]
One year or less	$ 4,170.3
One year to two years	3,219.6
Two years to three years	2,314.3
Three years to four years	3,470.7
After four years	7,199.9
Total available-for-sale securities	$ 20,374.8