ACQUISITIONS AND DIVESTITURES - Pro Forma Information (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
LHM Acquisition
Business Acquisition [Line Items]
Pro forma revenue	$ 15,431.5	$ 12,927.3
Pro forma net income	777.3	359.9
Jim Koons Dealerships
Business Acquisition [Line Items]
Pro forma revenue	17,540.4	18,516.1
Pro forma net income	$ 660.8	$ 1,092.9

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479328/805-10-50-2

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