Fair Value Measurements (Fair Value Inputs, Liabilities, Quantitative Information) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Dec. 31, 2020
Fair Value Inputs, Liabilities, Quantitative Information
Long-term Debt	$ 1,033.7	$ 1,033.4
Business Combination, Contingent Consideration, Liability, Noncurrent	5.0
Long-term debt, fair value	$ 1,000.0
Level 1 Inputs
Fair Value Inputs, Liabilities, Quantitative Information
Fair value level 1 inputs	quoted prices in active markets for identical liabilities (Level 1 inputs
Fair Value Measured at Net Asset Value Per Share [Member]
Fair Value Inputs, Liabilities, Quantitative Information
Deferred Compensation Plan Assets	$ 14.1	$ 14.4

Fair value level 1 inputs

No definition available.

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- Definition

Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled beyond one year or the normal operating cycle, if longer.

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- Definition

Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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- Definition

The fair value amount of long-term debt 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.

+ References

No definition available.

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