Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Additional Information (Detail)

v2.4.0.8
Long-Term Debt - Additional Information (Detail) (USD $)
3 Months Ended 6 Months Ended 6 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 6 Months Ended 6 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended
Jun. 30, 2014
Note
Agreement
Jun. 30, 2013
Jun. 30, 2014
Note
Agreement
Jun. 30, 2013
Dec. 31, 2013
May 09, 2013
Jun. 30, 2014
Assumed Notes [Member]
Jun. 30, 2014
2011 Credit Facility [Member]
Jun. 30, 2014
2011 Revolving Credit Facility [Member]
Jun. 30, 2014
2011 New Vehicle Floor Plan Facility [Member]
Jun. 30, 2014
Cash Flow Swap 15 [Member]
Jun. 30, 2014
Cash Flow Swap 16 [Member]
Jun. 30, 2014
Maximum [Member]
2011 Credit Facility [Member]
Jun. 30, 2014
Minimum [Member]
2011 Credit Facility [Member]
Jun. 30, 2014
2011 Used Vehicle Floor Plan Facility [Member]
2011 New Vehicle Floor Plan Facility [Member]
Jun. 30, 2014
2011 Used Vehicle Floor Plan Facility [Member]
Maximum [Member]
2011 New Vehicle Floor Plan Facility [Member]
Jun. 30, 2014
7.0% Senior Subordinated Notes Due 2022 [Member]
Dec. 31, 2013
7.0% Senior Subordinated Notes Due 2022 [Member]
Jul. 02, 2012
7.0% Senior Subordinated Notes Due 2022 [Member]
Jun. 30, 2014
Senior Subordinated Notes [Member]
Jul. 02, 2012
Senior Subordinated Notes [Member]
Jun. 30, 2014
5.0% Senior Subordinated Notes due 2023 [Member]
Dec. 31, 2013
5.0% Senior Subordinated Notes due 2023 [Member]
Jun. 30, 2014
Mortgage Notes [Member]
Property
Jun. 30, 2014
Required Ratio [Member]
Maximum [Member]
2011 Credit Facility [Member]
Jun. 30, 2014
Required Ratio [Member]
Minimum [Member]
2011 Credit Facility [Member]
Jun. 30, 2014
Derivative Instruments and Hedging Activities [Member]
Jun. 30, 2013
Derivative Instruments and Hedging Activities [Member]
Jun. 30, 2014
Derivative Instruments and Hedging Activities [Member]
Jun. 30, 2013
Derivative Instruments and Hedging Activities [Member]
Dec. 31, 2013
Derivative Instruments and Hedging Activities [Member]
Jun. 30, 2014
Derivative Instruments and Hedging Activities [Member]
Other Accrued Liabilities [Member]
Dec. 31, 2013
Derivative Instruments and Hedging Activities [Member]
Other Accrued Liabilities [Member]
Jun. 30, 2014
Derivative Instruments and Hedging Activities [Member]
Other Long-Term Liabilities [Member]
Dec. 31, 2013
Derivative Instruments and Hedging Activities [Member]
Other Long-Term Liabilities [Member]
Jun. 30, 2014
Derivative Instruments and Hedging Activities [Member]
Other Assets [Member]
Dec. 31, 2013
Derivative Instruments and Hedging Activities [Member]
Other Assets [Member]
Debt Instrument [Line Items]                                                                          
Maturity date of 2011 revolving credit facility and floor plan facility               Aug. 15, 2016                                                          
Increased borrowing capacity                 $ 175,000,000                                                        
Increased borrowing capacity                 225,000,000           605,000,000                                            
Borrowing base                 146,500,000                                                        
Letters of credit outstanding amount                 29,200,000                                                        
Carrying amount, Total 780,885,000   780,885,000   748,373,000   6,000,000   0               200,000,000 200,000,000       300,000,000 300,000,000                            
Borrowing availability amount                 117,300,000                                                        
Increase in credit facility borrowing capacity                               175,000,000                                          
Allocation of credit facility increase, percentage                   15.00%                                                      
Principal amount           300,000,000                         200,000,000                                    
Interest on notes 5.00%   5.00%       5.35%                   7.00% 7.00%       5.00% 5.00%                            
Notes maturity date     May 15, 2023                           Jul. 15, 2022                                        
Notes issued at a price of principal amount     100.00%                                 99.11%                                  
Notes issued yield maturity, percentage                                         7.125%                                
Interest payable description     Semi-annually in arrears on May 15 and November 15 of each year                           Semi-annually in arrears on January 15 and July 15 of each year                                        
Notes redeemed percentage of aggregate principal amount                                 35.00%         35.00%                              
Notes redemption price percentage of the par value                                 107.00%         105.00%                              
Notes redemption price percentage of the par value due to change of control                                 101.00%         101.00%                              
Debt instrument maximum allowed dividends per share                                 $ 0.10         $ 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 B Common Stock in excess of $0.10 per share. Sonic may only pay quarterly cash dividends on Sonic's Class A and B Common Stock if Sonic complies with the terms of the indenture governing the 7.0% 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 B Common Stock in excess of $0.10 per share. Sonic may only pay quarterly cash dividends on Sonic's Class A and 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%         25.00%                              
Indebtedness with outstanding balance                                 35,000,000         50,000,000                              
Debt default description under 5% and 7% notes                                 Sonic's obligations under the 7.0% Notes may be accelerated by the holders of 25% of the outstanding principal amount of the 7.0% Notes then outstanding if certain events of default occur, including (1) defaults in the payment of principal or interest when due; (2) defaults in the performance, or breach, of Sonic's covenants under the 7.0% Notes; and (3) certain defaults under other agreements under which Sonic or its subsidiaries have outstanding indebtedness in excess of $35.0 million         Sonic's obligations under the 5.0% Notes may be accelerated by the holders of 25% of the outstanding principal amount of the 5.0% Notes then outstanding if certain events of default occur, including (1) defaults in the payment of principal or interest when due; (2) defaults in the performance, or breach, of Sonic's covenants under the 5.0% Notes; and (3) certain defaults under other agreements under which Sonic or its subsidiaries have outstanding indebtedness in excess of $50.0 million                              
Notes redemption price percentage of the principal amount                                           100.00%                              
Number of notes payable 3   3                                                                    
Notes payable due date             October 2015 and August 2016                                 Between 2014 and 2033                          
Premium recorded on notes payable             7,300,000                                                            
Remaining unamortized premium balance             200,000                                                            
Debt weighted average interest rate on note                                               3.78%                          
Mortgage financing aggregate                                               271,600,000                          
Mortgage financing related to dealership properties                                               29                          
EBTDAR to rent ratio                         3.51 1.00                     1.50 1.00                      
Fair value of swap positions                                                     14,900,000   14,900,000   16,300,000 10,500,000 11,600,000     1,500,000 3,700,000
Fair value of swap positions                                                                   5,900,000 8,400,000    
Benefits and charges related to cash flow swaps not designated as hedges                                                     100,000 400,000 200,000 600,000              
Notional Forward 2   2                                                                    
Description of interest rate cash flow swap agreements     Swap agreements become effective in July 2016 and July 2015, respectively, and terminate in July 2017                                                                    
Interest rate Cash flow swap agreements                     25,000,000 100,000,000                                                  
Interest rate Cash flow swap agreements Maturity Date                     Jul. 31, 2017 Jul. 31, 2017                                                  
Incremental interest expense 3,000,000 2,900,000 5,900,000 5,800,000                                                                  
Net expense expected to be reclassified $ 6,500,000   $ 6,500,000