Corporate Investments And Funds Held For Clients (Expected Maturities Of Available-For-Sale Securities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014
Corporate Investments And Funds Held For Clients [Abstract]
One year or less	$ 4,697.5
One year to two years	3,754.4
Two years to three years	3,092.0
Three years to four years	2,098.3
After four years	6,686.0
Total available-for-sale securities	$ 20,328.2