Borrowings (Outstanding Borrowings) (Details) (USD $) In Millions				3 Months Ended
	Sep. 30, 2011	Jun. 30, 2011		Sep. 30, 2011 Term Loan Facility [Member]	Sep. 30, 2011 Revolving Credit Facility [Member]	Sep. 30, 2011 Senior Notes [Member]
Debt Instrument [Line Items]
Term loan facility, Short-term		$ 200.0	[1]
Revolving credit facility, Short-term		200.0	[1]
Total Short-term borrowings		400.0
Term loan facility, Long-term	490.0
Senior notes, Long-term	124.3	124.3
Total debt	614.3	524.3
Unused Available Capacity	$ 500.0				$ 500.0
Expiration Date				Sep. 01, 2016	Sep. 01, 2016	Jun. 01, 2017

[1] The outstanding borrowings of $200.0 million on the five-year term loan facility and $200.0 million on the five-year revolving credit facility that were entered into on March 29, 2007 (collectively "the 2007 Credit Facilities") were repaid with proceeds from the $490.0 million five-year term loan facility entered into on September 22, 2011.