Sonic Automotive, Inc. Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies - Summary of Lease Exit Accruals (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($)
Lease Exit [Roll Forward]
Balance at December 31, 2017	$ 6,478
Lease exit expense	2,697
Payments	(2,336)
Lease buyout/other	(580)
Balance at September 30, 2018	6,259
Component of lease exit expense in selling, general and administrative expenses	2,300
Component of lease exit expense in interest expense	100
Component of lease exit expense in income (loss) from operations and the sale of dealerships before tax	300
Component of lease exit payments in selling, general and administrative expenses	800
Component of lease exit payments in income (loss) from operations and the sale of dealerships before tax	$ 1,500