Borrowings (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Dec. 31, 2011	Dec. 31, 2011	Sep. 22, 2011
Debt Instrument [Line Items]
Spread over LIBOR (basis points)	550	550
Debt issuance costs incurred		$ 2.9
Repayment of short-term borrowings		400.0
Payments on long-term debt		20.0
2011 Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity			990.0
Spread over LIBOR (basis points)	125	125
Debt issuance costs incurred		3.0
Debt issuance cost expensed		0.1
Debt issuance cost capitalized	2.9	2.9
Accumulated Amortization of debt issuance costs	0.4	0.4
Five-Year Term Loan Facility [Member]
Debt Instrument [Line Items]
Loan in the duration of years		five
Credit facility maximum borrowing capacity			490.0
Minimum principal repayments on the loan		12.3
Basis of principal repayments on the loan		quarterly
First payment due on the loan		March 31, 2013
Final payment due on the loan		June 30, 2016
Total repayment before the balance of the loan becomes due in September 2016		171.5
Payments on long-term debt	20.0
Previous Five-Year Term Loan Facility [Member]
Debt Instrument [Line Items]
Repayment of short-term borrowings		200.0
Five-Year Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Loan in the duration of years		five
Credit facility maximum borrowing capacity			500.0
Annual facility fee (as basis points)		15
Previous Five-Year Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Repayment of short-term borrowings		200.0
Fixed-Rate Senior Notes [Member]
Debt Instrument [Line Items]
Fair value of the fixed-rate senior notes	$ 133.5	$ 133.5
Term Loan Facility [Member]
Debt Instrument [Line Items]
Expiration Date		Sep. 01, 2016
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Expiration Date		Sep. 01, 2016
Senior Notes [Member]
Debt Instrument [Line Items]
Expiration Date		Jun. 01, 2017