ACQUISITIONS - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Nov. 30, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Identifiable assets acquired and liabilities assumed
Goodwill		$ 1,661.8	$ 1,420.2	$ 997.1
Prime Automotive Group
Business Acquisition
Total consideration	$ 967.6	967.6
Identifiable assets acquired and liabilities assumed
Inventories		136.7
Property and equipment		266.8
Intangible franchise rights		135.3
Operating lease assets		58.3
Other assets		62.2
Total assets acquired		659.3
Operating lease liabilities		56.6
Other liabilities		38.3
Total liabilities assumed		94.9
Total identifiable net assets		564.4
Goodwill		$ 403.2
Assets held for sale	55.3
Liabilities held for sale	$ 1.7