DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Description (Details) $ in Millions	Dec. 11, 2023 USD ($) collisionCenter	Dec. 17, 2021 USD ($) collisionCenter usedVehicleStore	Dec. 31, 2023 dealership_location CollisionRepairCenters states franchise VehicleBrands
Business Organization [Line Items]
Number of franchises (in franchises) | franchise			208
Number of vehicle brands (in vehicle brands) | VehicleBrands			31
Number of dealership locations (in dealership locations) | dealership_location			158
Number of collision repair centers (in collision repair centers) | CollisionRepairCenters			37
Number of states (in states) | states			16
LHM Acquisition
Business Organization [Line Items]
Number of new vehicle dealerships acquired (in new vehicle dealerships)		54
Number of used cars stores acquired (in used cars stores) | usedVehicleStore		7
Number of collision centers acquired (in collision centers)		11
Aggregate purchase price | $		$ 3,193.9
Jim Koons Dealerships
Business Organization [Line Items]
Number of new vehicle dealerships acquired (in new vehicle dealerships)	20
Number of collision centers acquired (in collision centers)	6
Aggregate purchase price | $	$ 1,500.0