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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 | 1 Months Ended | 12 Months Ended
--- | --- | ---
Oct. 31, 2018 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investment in equity security | $ 50.0 | $ 0.0 | $ 50.0 | $ 0.0
Equity Securities without Readily Determinable Fair Value, Upward Adjustment |  | 25.7 | 0.0 | $ 0.0
Fixed Rate Debt [Member] | Carrying Value [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Fixed rate debt |  | 1,934.1 | 1,970.5 |
Fixed Rate Debt [Member] | Fair Value [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Fixed rate debt |  | 2,001.8 | 1,908.9 |
Nonrecurring [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Equity Securities without Readily Determinable Fair Value, Upward Adjustment |  | 25.7 | 0.0 |
Fair Value, Inputs, Level 3 [Member] | Nonrecurring [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Equity security without a readily determinable fair value |  | $ 75.7 | $ 0.0 |

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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=116654751&loc=SL75117539-209714 + Details
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- Definition Amount of gain from upward price adjustment on 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 (c) -URI http://asc.fasb.org/extlink&oid=116654751&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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- Definition The cash outflow associated with the purchase of all investments (debt, security, other) during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585 + Details
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