Indebtedness (Summary of Total Indebtedness) (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Current portion	$ (15.0)	$ (11.3)
Total debt	1,243.0	1,239.6
Total long-term debt	1,228.0	1,228.3
Derivatives assets	4.8	2.0
Series 2005 - 1 Swap [Member] \| Interest Rate Swaps [Member]
Derivatives assets	3.4	(3.7)
Series 2005-1 Notes [Member]
Notes payable	303.4	296.3
Series 2007-1 Notes [Member]
Notes payable	300.0	300.0
2008 Term Loan [Member]
Loan Payable	142.5	146.3
2010 Senior Notes [Member]
Notes payable	497.1	497.0
Unamortized discount	$ 2.9	$ 3.0

Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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Carrying value as of the balance sheet date of the sum of short-term debt and current maturities of long-term debt and capital lease obligations, which are due within one year (or one business cycle if longer).

+ References

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The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name FASB Staff Position (FSP)
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Fair value of derivative asset, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

+ References

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Including the current and noncurrent portions, aggregate carrying value as of the balance sheet date of loans payable (with maturities initially due after one year or beyond the operating cycle if longer).

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Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year (current maturities) or the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

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