Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

v3.10.0.1
Document and Entity Information - shares
 6 Months Ended
Jun. 30, 2018
Jul. 25, 2018
Document Information [Line Items]    
Entity Registrant Name SONIC AUTOMOTIVE INC  
Entity Central Index Key 0001043509  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Document Type 10-Q  
Document Period End Date Jun. 30, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q2  
Trading Symbol SAH  
Amendment Flag false  
Class A common stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   30,682,181
Class B common stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   12,029,375