Debt (Schedule Of Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Principal debt outstanding	$ 858.1	$ 883.1
Unamortized debt financing costs	(7.9)	(9.5)
Less current portion and short-term debt	32.5	25.0
Long-term debt, less current installments	$ 817.7	$ 848.6
Principal debt outstanding, Weighted average year- end interest rate	3.43%	3.54%
Term Loan A Due 2021 [Member]
Debt Instrument [Line Items]
Principal debt outstanding	$ 577.5	$ 600.0
Principal debt outstanding, Weighted average year- end interest rate	3.24%	3.29%
Term Loan B Due 2023 [Member]
Debt Instrument [Line Items]
Principal debt outstanding	$ 245.6	$ 248.1
Principal debt outstanding, Weighted average year- end interest rate	4.25%	4.58%
Tax Exempt Bonds Due 2041 [Member]
Debt Instrument [Line Items]
Principal debt outstanding	$ 35.0	$ 35.0
Principal debt outstanding, Weighted average year- end interest rate	0.79%	0.45%
Current Portion And Short-Term Debt [Member]
Debt Instrument [Line Items]
Less current portion and short-term debt	$ 32.5	$ 25.0
Current portion and short-term debt, Weighted average year-end interest rate	3.32%	3.42%
Long-term Debt [Member]
Debt Instrument [Line Items]
Long-term debt	$ 850.2	$ 873.6
Principal debt outstanding, Weighted average year- end interest rate	3.43%	3.54%
Long-Term Debt, Less Current Portion [Member]
Debt Instrument [Line Items]
Long-term debt, less current installments	$ 817.7	$ 848.6
Long-term debt, Weighted average year-end interest rate	3.43%	3.54%

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Section S99
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 210
-Section S99
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-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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