Acquisitions and Dispositions (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019 USD ($) franchise dealership
Acquisitions and Dispositions (Textual) [Abstract]
Aggregate consideration paid for dealerships | $	$ 97.0
Net gain on dispositions | $	$ 5.0
U.S.
Acquisitions and Dispositions (Textual) [Abstract]
Number of dealerships acquired | dealership	2
Number of franchises acquired	4
Number of dealerships opened | dealership	1
Number of franchises opened	1
Number of dealerships disposed	4
Number of franchises disposed	7
Number of franchises terminated	2
U.K.
Acquisitions and Dispositions (Textual) [Abstract]
Number of dealerships acquired | dealership	4
Number of franchises acquired	5
Number of dealerships opened | dealership	1
Number of franchises opened	1
Number of dealerships disposed | dealership	3
Number of franchises disposed	4
Brazil
Acquisitions and Dispositions (Textual) [Abstract]
Number of dealerships disposed | dealership	1
Number of franchises disposed	1