Label	Element	Value
FranchisedDealershipMember [Member]
Gain on Acquisition of Remaining Equity Interest in Joint Venture	sah_GainOnAcquisitionOfRemainingEquityInterestInJointVenture	$ 3,500,000
Echo Park [Member]
Real Estate, Fair Value	sah_RealEstateFairValue	55,500,000
Gain (Loss) on Termination of Lease	us-gaap_GainLossOnTerminationOfLease	(3,000,000.0)
Closed Store Accrued Expenses	sah_ClosedStoreAccruedExpenses	2,100,000
Vehicle Inventory Valuation Adjustments	sah_VehicleInventoryValuationAdjustments	10,000,000.0
Retained Earnings [Member]
Net Income (Loss) Attributable to Parent	us-gaap_NetIncomeLoss	$ 216,000,000.0