Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis (Detail)

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Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis (Detail) - USD ($)
 12 Months Ended
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