Document and Entity Information	3 Months Ended
	Mar. 31, 2013	Apr. 15, 2013 Common Class A	Apr. 15, 2013 Common Class B
Entity Registrant Name	SONIC AUTOMOTIVE INC
Entity Central Index Key	0001043509
Document Type	10-Q
Document Period End Date	Mar. 31, 2013
Amendment Flag	false
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		40,932,510	12,029,375