Fair Value - Recurring Fair Value Measures (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Liabilities:
Derivatives - Interest Rate Swap	$ (0.5)
Fair Value, Measurements, Recurring [Member] \| Total [Member]
Assets:
Equity Securities	18.9	19.4
Available-for-sale Securities		14.2
Money Market Funds	6.0	0.8
Total Fair Value of Assets	32.9	34.4
Liabilities:
Deferred Compensation	13.3	13.3
Derivatives - Interest Rate Swap	0.5
Total Fair Value of Liabilities	13.8	13.3
Total Net Fair Value of Assets (Liabilities)	19.1	21.1
Fair Value, Measurements, Recurring [Member] \| Total [Member] \| Corporate Debt Securities [Member]
Assets:
Available-for-sale Securities	8.0	7.5
Fair Value, Measurements, Recurring [Member] \| Total [Member] \| Debt Securities Issued by States of the United States (ARS) [Member]
Assets:
Available-for-sale Securities		6.7
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member]
Assets:
Equity Securities	18.9	19.4
Available-for-sale Securities		0
Money Market Funds	6.0	0.8
Total Fair Value of Assets	24.9	20.2
Liabilities:
Deferred Compensation	0	0
Derivatives - Interest Rate Swap	0
Total Fair Value of Liabilities	0	0
Total Net Fair Value of Assets (Liabilities)	24.9	20.2
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member] \| Corporate Debt Securities [Member]
Assets:
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member] \| Debt Securities Issued by States of the United States (ARS) [Member]
Assets:
Available-for-sale Securities		0
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member]
Assets:
Equity Securities	0	0
Available-for-sale Securities		7.5
Money Market Funds	0	0
Total Fair Value of Assets	8.0	7.5
Liabilities:
Deferred Compensation	13.3	13.3
Derivatives - Interest Rate Swap	0.5
Total Fair Value of Liabilities	13.8	13.3
Total Net Fair Value of Assets (Liabilities)	(5.8)	(5.8)
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Corporate Debt Securities [Member]
Assets:
Available-for-sale Securities	8.0	7.5
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Debt Securities Issued by States of the United States (ARS) [Member]
Assets:
Available-for-sale Securities		0
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member]
Assets:
Equity Securities	0	0
Available-for-sale Securities		6.7
Money Market Funds	0	0
Total Fair Value of Assets	0	6.7
Liabilities:
Deferred Compensation	0	0
Derivatives - Interest Rate Swap	0
Total Fair Value of Liabilities	0	0
Total Net Fair Value of Assets (Liabilities)	0	6.7
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member] \| Corporate Debt Securities [Member]
Assets:
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member] \| Debt Securities Issued by States of the United States (ARS) [Member]
Assets:
Available-for-sale Securities		$ 6.7

This element represents the aggregate of the assets and liabilities reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

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For an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading.

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Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents investments accounted for under the equity method of accounting as of the balance sheet date.

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Fair value as of the balance sheet date of all interest rate derivative liabilities designated as cash flow hedging instruments.

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Investment in short-term money-market instruments (such as commercial paper, banker's acceptances, repurchase agreements, government securities, certificates of deposit, and so forth) which are highly liquid (that is, readily convertible to known amounts of cash) and so near their maturity that they present an insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify as cash equivalents by definition. Original maturity means an original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

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