Borrowings (Outstanding Borrowings) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended			6 Months Ended				6 Months Ended		6 Months Ended		6 Months Ended
	Dec. 31, 2011		Jun. 30, 2011	Dec. 31, 2011 Term Loan Facility [Member]	Dec. 31, 2011 Revolving Credit Facility [Member]	Dec. 31, 2011 Senior Notes [Member]	Sep. 22, 2011 2011 Credit Facility [Member]	Dec. 31, 2011 Five-Year Term Loan Facility [Member]	Sep. 22, 2011 Five-Year Term Loan Facility [Member]	Dec. 31, 2011 Five-Year Revolving Credit Facility [Member]	Sep. 22, 2011 Five-Year Revolving Credit Facility [Member]	Dec. 31, 2011 Previous Five-Year Term Loan Facility [Member]	Dec. 31, 2011 Previous Five-Year Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Term loan facility, Short-term borrowings		[1]	$ 200.0
Revolving credit facility, Short-term borrowings		[1]	200.0
Total Short-term borrowings			400.0
Term loan facility, Long-term debt	470.0
Senior notes, Long-term debt	124.3		124.3
Total debt	594.3		524.3
Unused Available Capacity	500.0				500.0
Expiration Date				Sep. 01, 2016	Sep. 01, 2016	Jun. 01, 2017
Loan in the duration of years								five		five
Credit facility maximum borrowing capacity							990.0		490.0		500.0
Repayments of Short-term Debt	$ 400.0											$ 200.0	$ 200.0

[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.