Corporate Investments And Funds Held For Clients (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2017		Jun. 30, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	$ 21,901.1	[1]	$ 21,605.0	[2]
Earliest corporate bond maturity date	July 2017
Latest corporate bond maturity date	March 2026
Earliest non-callable debt maturity date	September 2017
Latest non-callable debt maturity date	February 2025
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	$ 27,189.4		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	79.00%
Federal Home Loan Banks [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	$ 2,554.7
Federal Farm Credit Banks [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	803.2
Fixed Rate Credit Card [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	2,362.2
Asset-Backed Auto Loan Receivables [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	1,428.3
Asset-Backed Equipment Lease Receivable [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	431.0
Rate Reduction Receivable [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	239.8
Sovereign Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	129.3
Foreign Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	110.7
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	95.9
Funds Held For Clients [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	21,890.3		21,573.7
Corporate Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value	$ 10.8		$ 31.3

[1] Included within available-for-sale securities are corporate investments with fair values of $10.8 million and funds held for clients with fair values of $21,890.3 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 $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.