Corporate Investments And Funds Held For Clients (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2015		Jun. 30, 2015
Schedule of Available-for-sale Securities [Line Items]
Earliest Corporate bond debt maturity date	October 2015
Latest corporate debt maturity date	June 2023
Earliest U.S. Treasury maturity date	November 2015
Latest U.S Treasury maturity date	August 2025
Available-for-sale securities - Fair Value	$ 20,374.8	[1]	$ 20,873.8	[2]
Length of shortest cash flow of residential mortgages used as collateral for companies mortgage backed securities (in years)	15 years
Length of longest cash flow of residential mortgages used as collateral for company's mortgage backed securities (in years)	30 years
Client Fund Obligation repayment period	1 year
Client funds obligations	$ 24,240.2		24,650.5
Client funds investments with original maturities	ninety days or less
Percent of Level Two Investment Pricing Inputs Provided by Pricing Service	80.00%
Federal Home Loan Banks [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	$ 3,968.5
Federal Farm Credit Banks [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	1,006.8
Fixed Rate Credit Card [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	1,806.1
Asset-Backed Auto Loan Receivables [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	455.4
Rate Reduction [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	239.4
Supranational Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	254.2
Sovereign Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	331.0
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	92.6
Fair Value, Inputs, Level 1 [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	0.0		0.0
Fair Value, Inputs, Level 3 [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	$ 0.0		$ 0.0

[1] Included within available-for-sale securities are corporate investments with fair values of $48.5 million and funds held for clients with fair values of $20,326.3 million. All available-for-sale securities were included in Level 2.

[2] Included within available-for-sale securities are corporate investments with fair values of $55.5 million and funds held for clients with fair values of $20,818.3 million. All available-for-sale securities were included in Level 2.