Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

v3.8.0.1
Document and Entity Information - shares
9 Months Ended
Sep. 30, 2017
Oct. 23, 2017
Document and Entity Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q3  
Trading Symbol SAH  
Entity Registrant Name SONIC AUTOMOTIVE INC  
Entity Central Index Key 0001043509  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Common Class A [Member]    
Document and Entity Information [Line Items]    
Entity Common Stock, Shares Outstanding   31,166,205
Common Class B [Member]    
Document and Entity Information [Line Items]    
Entity Common Stock, Shares Outstanding   12,029,375