Debt (Schedule Of Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Principal debt outstanding	$ 615.0	$ 825.6
Unamortized debt financing costs	(4.2)	(5.8)
Less current portion and short-term debt	6.3	55.0
Long-term debt, less current installments	604.5	764.8
Revolving Credit Facility Due 2024 [Member]
Debt Instrument [Line Items]
Principal debt outstanding	115.0
Term Loan A Due 2021 [Member]
Debt Instrument [Line Items]
Principal debt outstanding		547.5
Term Loan A Due 2024 [Member]
Debt Instrument [Line Items]
Principal debt outstanding	500.0
Term Loan B Due 2023 [Member]
Debt Instrument [Line Items]
Principal debt outstanding		243.1
Tax Exempt Bonds Due 2041 [Member]
Debt Instrument [Line Items]
Principal debt outstanding		35.0
Current Portion And Short-Term Debt [Member]
Debt Instrument [Line Items]
Less current portion and short-term debt	6.3	55.0
Long-term Debt [Member]
Debt Instrument [Line Items]
Long-term debt	610.8	819.8
Long-Term Debt, Less Current Portion [Member]
Debt Instrument [Line Items]
Long-term debt, less current installments	$ 604.5	$ 764.8

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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