Annual report pursuant to Section 13 and 15(d)

Long-Term Debt - Additional Information (Detail)

v3.3.1.900
Long-Term Debt - Additional Information (Detail)
3 Months Ended 12 Months Ended
May. 09, 2013
USD ($)
Jul. 02, 2012
USD ($)
shares
Dec. 31, 2015
USD ($)
shares
Sep. 30, 2015
USD ($)
Jun. 30, 2015
USD ($)
Agreement
Mar. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
shares
Sep. 30, 2014
USD ($)
Jun. 30, 2014
USD ($)
Mar. 31, 2014
USD ($)
Dec. 31, 2015
USD ($)
$ / shares
shares
Dec. 31, 2014
USD ($)
shares
Dec. 31, 2013
USD ($)
Debt Instrument [Line Items]                          
Retained earnings     $ 457,010,000       $ 376,353,000       $ 457,010,000 $ 376,353,000  
Net income (loss)     $ 31,058,000 $ 26,505,000 $ 14,781,000 $ 13,967,000 26,126,000 $ 24,712,000 $ 26,993,000 $ 19,386,000 $ 86,311,000 97,217,000 $ 81,618,000
Convertible senior notes due                         2029
Minimum EBTDAR to rent ratio     381.00%               381.00%    
Notional Forward | Agreement         4                
Incremental interest expense                     $ 7,800,000 10,700,000 $ 11,800,000
Net expense expected to be reclassified     $ 3,200,000               3,200,000    
Derivative Instruments and Hedging Activities [Member]                          
Debt Instrument [Line Items]                          
Fair value of swap positions     10,000,000       11,100,000       10,000,000 11,100,000  
Benefits and charges related to cash flow swaps not designated as hedges                     600,000 500,000 $ 900,000
Derivative Instruments and Hedging Activities [Member] | Other Accrued Liabilities [Member]                          
Debt Instrument [Line Items]                          
Fair value of swap positions     5,100,000       8,200,000       5,100,000 8,200,000  
Derivative Instruments and Hedging Activities [Member] | Other Long-Term Liabilities [Member]                          
Debt Instrument [Line Items]                          
Fair value of swap positions     $ 4,900,000       3,500,000       $ 4,900,000 3,500,000  
Derivative Instruments and Hedging Activities [Member] | Other Assets [Member]                          
Debt Instrument [Line Items]                          
Fair value of swap positions             $ 600,000         $ 600,000  
Assumed Notes [Member]                          
Debt Instrument [Line Items]                          
Stated interest rate on debt agreement     5.35%               5.35%    
Premium recorded on notes payable     $ 7,300,000               $ 7,300,000    
Outstanding principal balance     800,000               $ 800,000    
Notes payable due date                     August 2016    
Mortgage Notes [Member]                          
Debt Instrument [Line Items]                          
Outstanding principal balance     $ 319,400,000               $ 319,400,000    
Notes payable due date                     Between 2016 and 2033    
Debt weighted average interest rate on note     3.74%               3.74%    
Mortgage financing aggregate     $ 69,100,000               $ 69,100,000    
Percentage of operating locations related to mortgage financing                     37.00%    
Required Ratio [Member]                          
Debt Instrument [Line Items]                          
Minimum EBTDAR to rent ratio     150.00%               150.00%    
Common Class A [Member]                          
Debt Instrument [Line Items]                          
Common stock, shares issued | shares     62,586,381       62,046,966       62,586,381 62,046,966  
2014 Credit Facility [Member]                          
Debt Instrument [Line Items]                          
Maturity date of revolving credit facility and floor plan facility                     Aug. 15, 2019    
Retained earnings     $ 0               $ 0    
Net income (loss)                     $ 0    
Minimum EBTDAR to rent ratio     381.00%               381.00%    
2014 Credit Facility [Member] | Required Ratio [Member]                          
Debt Instrument [Line Items]                          
Minimum EBTDAR to rent ratio     150.00%               150.00%    
2014 Revolving Credit Facility [Member]                          
Debt Instrument [Line Items]                          
Current borrowing capacity     $ 225,000,000               $ 225,000,000    
Maximum borrowing capacity     275,000,000               275,000,000    
Borrowing base     208,200,000               208,200,000    
Letters of credit outstanding amount     22,900,000               22,900,000    
2014 Revolving Credit Facility     4,203,000               4,203,000    
Borrowing availability amount     181,100,000               181,100,000    
2014 Floor Plan Facilities [Member]                          
Debt Instrument [Line Items]                          
Maximum borrowing capacity     800,000,000               800,000,000    
Increase in credit facility borrowing capacity     1,000,000,000               $ 1,000,000,000    
2014 Used Vehicle Floor Plan Facility [Member]                          
Debt Instrument [Line Items]                          
Allocation of credit facility increase, percentage                     20.00%    
7.0% Senior Subordinated Notes Due 2022 [Member]                          
Debt Instrument [Line Items]                          
Retained earnings     $ 0               $ 0    
Net income (loss)                     $ 0    
Principal amount   $ 200,000,000                      
Stated interest rate on debt agreement   7.00% 7.00%       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    
Notes redemption price percentage of the par value due to change of control                     101.00%    
Debt instrument maximum allowed dividends per share | $ / shares                     $ 0.10    
Restrictive covenants under 2011 credit facilities and 7 % notes with 5% notes                     Specifically, the indenture governing Sonic’s 7.0% Notes limits Sonic’s ability to pay quarterly cash dividends on Sonic’s Class A and Class B common stock in excess of $0.10 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 7.0%    
Outstanding principal amount of the 7.0% notes                     25.00%    
7.0% Senior Subordinated Notes Due 2022 [Member] | Minimum [Member]                          
Debt Instrument [Line Items]                          
Indebtedness with outstanding balance under other agreements                     $ 35,000,000    
5.0% Senior Subordinated Notes due 2023 [Member]                          
Debt Instrument [Line Items]                          
Retained earnings     $ 0               0    
Net income (loss)                     $ 0    
Principal amount $ 300,000,000                        
Stated interest rate on debt agreement 5.00%   5.00%       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    
Notes redemption price percentage of the par value due to change of control                     101.00%    
Debt instrument maximum allowed dividends per share | $ / shares                     $ 0.10    
Restrictive covenants under 2011 credit facilities and 7 % notes with 5% notes                     Specifically, the indenture governing Sonic’s 5.0% Notes limits Sonic’s ability to pay quarterly cash dividends on Sonic’s Class A and Class B common stock in excess of $0.10 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 5.0% Notes.    
Outstanding principal amount of the 7.0% notes                     25.00%    
Notes redeemed percentage of aggregate principal amount                     35.00%    
Notes redemption price percentage of the par value                     105.00%    
Notes redemption price percentage of the principal amount                     100.00%    
5.0% Senior Subordinated Notes due 2023 [Member] | Minimum [Member]                          
Debt Instrument [Line Items]                          
Indebtedness with outstanding balance under other agreements                     $ 50,000,000    
5.0% Senior Subordinated Notes due 2023 [Member] | Common Class A [Member]                          
Debt Instrument [Line Items]                          
Common stock, shares issued | shares   4,100,000                      
9.0% Senior Subordinated Notes due 2018 [Member]                          
Debt Instrument [Line Items]                          
Stated interest rate on debt agreement 9.00%                        
Convertible senior notes due                     2018