Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Additional Information (Detail)

v3.7.0.1
Long-Term Debt - Additional Information (Detail) - USD ($)
3 Months Ended
Mar. 27, 2017
Mar. 10, 2017
Sep. 30, 2016
May 09, 2013
Jul. 02, 2012
Mar. 31, 2017
Mar. 31, 2016
Dec. 31, 2016
Debt Instrument [Line Items]                
Loss on repurchase of debt instrument           $ 14,607,000    
Incremental interest expense           1,200,000 $ 1,300,000  
Net expense expected to be reclassified           1,600,000    
Derivative Instruments and Hedging Activities [Member]                
Debt Instrument [Line Items]                
Fair value of swap positions           1,500,000   $ 3,700,000
Expense related to cash flow swaps not designated as hedges           100,000 $ 100,000  
Derivative Instruments and Hedging Activities [Member] | Other Current Assets [Member]                
Debt Instrument [Line Items]                
Fair value of swap positions           200,000   2,800,000
Derivative Instruments and Hedging Activities [Member] | Other Assets [Member]                
Debt Instrument [Line Items]                
Fair value of swap positions           2,700,000   2,800,000
Derivative Instruments and Hedging Activities [Member] | Other Accrued Liabilities [Member]                
Debt Instrument [Line Items]                
Fair value of swap positions           2,800,000   4,100,000
Derivative Instruments and Hedging Activities [Member] | Other Long-Term Liabilities [Member]                
Debt Instrument [Line Items]                
Fair value of swap positions           1,600,000   $ 2,400,000
Mortgage Notes [Member]                
Debt Instrument [Line Items]                
Mortgage financing aggregate           $ 19,900,000    
Debt weighted average interest rate on note           3.95%    
Outstanding principal balance           $ 418,400,000    
Percentage of operating locations related to mortgage financing           50.00%    
Notes payable due date           between 2017 and 2033    
2016 Credit Facility [Member]                
Debt Instrument [Line Items]                
Maturity date of revolving credit facility and floor plan facility           Nov. 30, 2021    
Minimum EBTDAR to rent ratio           396.00%    
2016 Credit Facility [Member] | Required Ratio [Member]                
Debt Instrument [Line Items]                
Minimum EBTDAR to rent ratio           150.00%    
2016 Credit Facility [Member] | Minimum [Member]                
Debt Instrument [Line Items]                
Net income and retained earnings free of restrictions           $ 126,600,000    
2016 Revolving Credit Facility [Member]                
Debt Instrument [Line Items]                
Current borrowing capacity           250,000,000    
Maximum borrowing capacity           300,000,000    
Borrowing base           204,800,000    
Letters of credit outstanding amount           17,300,000    
2016 Revolving Credit Facility           0    
Borrowing availability amount           $ 187,500,000    
7.0% Senior Subordinated Notes Due 2022 [Member]                
Debt Instrument [Line Items]                
Principal amount         $ 200,000,000      
Stated interest rate on debt agreement         7.00% 7.00%   7.00%
Notes issued at a price of principal amount         99.11%      
Notes issued yield maturity, percentage         7.125%      
Notes maturity date           Jul. 15, 2022    
Interest payable description           semi-annually in arrears on January 15 and July 15 of each year    
Cash paid to extinguish of debt instrument including early redemption premium and accrued and unpaid interest $ 213,700,000              
Loss on repurchase of debt instrument $ 14,600,000              
5.0% Senior Subordinated Notes due 2023 [Member]                
Debt Instrument [Line Items]                
Principal amount       $ 300,000,000        
Stated interest rate on debt agreement       5.00%   5.00%   5.00%
Notes issued at a price of principal amount       100.00%        
Notes maturity date           May 15, 2023    
Interest payable description           semi-annually in arrears on May 15 and November 15 of each year    
Outstanding notes repurchased amount     $ 10,700,000          
Repurchase amount paid in cash, plus accrued and unpaid interest related thereto     $ 10,600,000          
6.125% Senior Subordinated Notes due 2027 [Member]                
Debt Instrument [Line Items]                
Principal amount   $ 250,000,000            
Stated interest rate on debt agreement   6.125%       6.125%   6.125%
Notes issued at a price of principal amount   100.00%            
Notes issued yield maturity, percentage   6.125%            
Notes maturity date           Mar. 15, 2027    
Interest payable description           semi-annually in arrears on March 15 and September 15 of each year    
Notes redemption price percentage of the principal amount           100.00%    
Redemption Price           106.125%    
Notes redemption price percentage of the par value due to change of control           101.00%    
Debt instrument maximum allowed dividends per share           $ 0.12    
Restrictive covenants under credit facilities and 6.125% notes           Specifically, the indenture governing the 6.125% Notes limits Sonic’s ability to pay quarterly cash dividends on Sonic’s Class A and Class B common stock in excess of $0.12 per share. Sonic may only pay quarterly cash dividends on Sonic’s Class A and Class B common stock if Sonic complies with the terms of the indenture governing the 6.125% Notes.    
Outstanding principal amount of the 6.125% notes           25.00%    
6.125% Senior Subordinated Notes due 2027 [Member] | Maximum [Member]                
Debt Instrument [Line Items]                
Notes redemption price percentage of the principal amount           35.00%    
6.125% Senior Subordinated Notes due 2027 [Member] | Minimum [Member]                
Debt Instrument [Line Items]                
Indebtedness with outstanding balance under other agreements           $ 50,000,000