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Financial Instruments And Fair Value Measurements (Summary Of Carrying Values And Fair Values Of Fixed Rate Debt) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2020 | Sep. 30, 2020 | Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Investment in security with readily determinable fair value | $ 288.5 | $ 288.5 |
Investment in equity security with readily determinable fair value, unrealized gain (loss) | (2.0) | 212.7 |
Investment in equity securities without readily determinable fair values | 50.0 | 50.0 |
Fixed Rate Debt [Member] | Carrying Value [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Fixed rate debt | 2,089.7 | 2,089.7 | $ 1,934.1
Fixed Rate Debt [Member] | Fair Value [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Fixed rate debt | $ 2,306.0 | $ 2,306.0 | $ 2,001.8

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- Definition Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740 + Details
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- Definition Amount of unrealized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(3)(d)) -URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=120269885&loc=SL75117546-209714 + Details
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- Definition Amount of investment in equity security without readily determinable fair value. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120269885&loc=SL75117539-209714 + Details
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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. + Details
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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. + Details
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