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Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis (Detail) - USD ($) | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items] |  |
Total Gain (loss) on goodwill | $ (900,000) | $ 0
Fair Value, Measurements, Nonrecurring [Member] |  |
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items] |  |
Long-lived assets held and used | 1,146,881,000 |
Goodwill | 525,780,000 |
Franchise assets | 69,900,000 |
Total Gain (loss) on long-lived assets held and used | (4,894,000) |
Total Gain (loss) on goodwill | (899,000) |
Total Gain (loss) on franchise assets | (3,600,000) |
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items] |  |
Long-lived assets held and used | 1,146,881,000 |
Goodwill | 525,780,000 |
Franchise assets | $ 69,900,000 |

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- Definition Fair value portion of asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19190-110258 + Details
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- Definition Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13854-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13777-109266 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
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