Debt (Schedule Of Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Principal debt outstanding	$ 883.1	$ 993.0
Unamortized debt financing costs	(9.5)	(4.7)
Less current portion and short-term debt	25.0	52.1
Long-term debt, less current installments	$ 848.6	$ 936.2
Principal debt outstanding, Weighted average year- end interest rate	3.54%	3.28%
Term Loan A Due 2021 [Member]
Debt Instrument [Line Items]
Principal debt outstanding	$ 600.0	$ 496.0
Principal debt outstanding, Weighted average year- end interest rate	3.29%	3.24%
Term Loan B Due 2023 [Member]
Debt Instrument [Line Items]
Principal debt outstanding	$ 248.1	$ 461.9
Principal debt outstanding, Weighted average year- end interest rate	4.58%	3.50%
Tax Exempt Bonds Due 2041 [Member]
Debt Instrument [Line Items]
Principal debt outstanding	$ 35.0	$ 35.1
Principal debt outstanding, Weighted average year- end interest rate	0.45%	0.87%
Current Portion And Short-Term Debt [Member]
Debt Instrument [Line Items]
Less current portion and short-term debt	$ 25.0	$ 52.1
Current portion and short-term debt, Weighted average year-end interest rate	3.42%	3.26%
Long-term Debt [Member]
Debt Instrument [Line Items]
Long-term debt	$ 873.6	$ 988.3
Long-term debt, Weighted average year- end interest rate	3.54%	3.28%
Long-Term Debt, Less Current Portion [Member]
Debt Instrument [Line Items]
Long-term debt, less current installments	$ 848.6	$ 936.2
Principal debt outstanding, Weighted average year- end interest rate	3.54%	3.28%

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
-Section 45
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-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

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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
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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