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Financial Instruments And Fair Value Measurements (Narrative) (Details) - USD ($) | 6 Months Ended
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Jun. 30, 2017 | Jun. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Franchise rights impairment | $ 0 | $ 0
Goodwill [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Date of Annual Goodwill and Indefinite Lived Intangible Assets Impairment Test | April 30 | April 30
Franchise Rights [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Date of Annual Goodwill and Indefinite Lived Intangible Assets Impairment Test | April 30 | April 30

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- Definition The date of the annual goodwill and indefinite-lived franchise rights impairment test. + References No definition available. + 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 Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275 + Details
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