Corporate Investments And Funds Held For Clients (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2016		Jun. 30, 2016
Schedule of Available-for-sale Securities [Line Items]
Earliest Corporate bond debt maturity date	October 2016
Latest corporate debt maturity date	May 2024
Available-for-sale securities - Fair Value	$ 21,751.0	[1]	$ 21,605.0	[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	$ 24,349.1		$ 33,331.8
Client funds investments with original maturities	ninety days or less
Percentage Of The Available-For-Sale Securities Were Rated AAA Or AA	80.00%
Earliest U.S. Treasury maturity date	October 2016
Latest U.S Treasury maturity date	September 2024
Federal Home Loan Banks [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	$ 3,024.7
Federal Farm Credit Banks [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	944.6
Fixed Rate Credit Card [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	2,285.4
Asset-Backed Auto Loan Receivables [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	1,270.7
Asset-Backed Equipment Lease Receivable [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	382.3
Rate Reduction [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	250.2
Supranational Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	188.6
Sovereign Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	166.6
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	103.1
Fair Value, Inputs, Level 1 [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	0.0
Fair Value, Inputs, Level 3 [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - Fair Value	$ 0.0

[1] Included within available-for-sale securities are corporate investments with fair values of $48.8 million and funds held for clients with fair values of $21,702.2 million. All available-for-sale securities were included in Level 2 of the fair value hierarchy.

[2] Included within available-for-sale securities are corporate investments with fair values of $31.3 million and funds held for clients with fair values of $21,573.7 million. All available-for-sale securities were included in Level 2 of the fair value hierarchy.