Corporate Investments And Funds Held For Clients (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Sep. 30, 2013		Jun. 30, 2013
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	$ 18,677.8	[1]	$ 18,838.7	[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	16,718.0		21,956.3
Client funds investments with original maturities	90 days or less
Percentage of the available-for-sale securities were rated AAA or AA	84.00%
Federal Home Loan Banks [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	4,390.7		4,325.4
Federal Farm Credit Banks [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	1,228.5		1,229.0
Fixed Rate Credit Card [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	898.0		904.5
Asset-Backed Auto Loan Receivables [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	313.1		315.7
Rate Reduction [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	86.8		95.4
Supranational Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	434.6		426.9
Sovereign Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	417.3		415.4
Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	136.9		163.5
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	103.9		112.6
Fair Value, Inputs, Level 1 [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	8.0		9.5
Corporate Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	3,090.9		342.0
Funds Held For Clients [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	$ 15,586.9		$ 18,496.7
Earliest [Member] | Corporate Bond Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Date	Oct. 01, 2013
Earliest [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Date	Oct. 01, 2013
Latest [Member] | Corporate Bond Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Date	Jun. 01, 2023
Latest [Member] | US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Date	May 01, 2023

[1] Included within available-for-sale securities are corporate investments with fair values of $3,090.9 million and funds held for clients with fair values of $15,586.9 million. At September 30, 2013, Level 1 securities included $8.0 million of corporate investments classified within "Other securities." All remaining available-for-sale securities were included in Level 2.

[2] Included within available-for-sale securities are corporate investments with fair values of $342.0 million and funds held for clients with fair values of $18,496.7 million. At June 30, 2013, Level 1 securities included $9.5 million of corporate investments classified within "Other securities." All remaining available-for-sale securities were included in Level 2.