Acquisitions (Details) - store	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Collision Centers [Member]
Business Acquisition [Line Items]
Number of stores purchased		7	1
Dealerships [Member]
Business Acquisition [Line Items]
Number of stores purchased		1	20
California | Premium Luxury Dealership [Member]
Business Acquisition [Line Items]
Number of stores purchased	1
Maryland | Collision Centers [Member]
Business Acquisition [Line Items]
Number of stores purchased	1
Texas | Collision Centers [Member]
Business Acquisition [Line Items]
Number of stores purchased	1