CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
REVENUES	$ 16,222.1	$ 13,481.9	$ 10,600.2
COST OF SALES	13,256.9	11,041.2	8,866.1
GROSS PROFIT	2,965.2	2,440.7	1,734.1
Selling, general and administrative expenses	1,783.3	1,477.2	1,138.2
Depreciation and amortization expense	88.4	77.4	73.5
Asset impairments	2.1	1.7	26.7
INCOME FROM OPERATIONS	1,091.4	884.4	495.7
INTEREST EXPENSE:
Floorplan interest expense	27.3	27.6	39.2
Other interest expense, net	77.5	55.8	61.9
Loss on extinguishment of debt	0.0	0.0	13.7
Other expense	1.2	0.0	0.0
INCOME BEFORE INCOME TAXES	985.3	800.9	380.8
Provision for income taxes	231.1	175.5	84.2
Net income from continuing operations	754.2	625.4	296.7
Net loss from discontinued operations	(2.7)	(73.3)	(10.2)
NET INCOME	$ 751.5	$ 552.1	$ 286.5
BASIC EARNINGS PER SHARE:
Basic earnings per share continuing operations (in dollars per shares)	$ 47.46	$ 34.23	$ 16.11
Basic earnings per share discontinuing operations (in dollars per shares)	(0.17)	(4.01)	(0.55)
Basic earnings per share (in dollars per shares)	47.29	30.22	15.55
DILUTED EARNINGS PER SHARE:
Diluted earnings per share continuing operations (in dollars per shares)	47.31	34.11	16.06
Diluted earnings per share discontinuing operations (in dollars per shares)	(0.17)	(4.00)	(0.55)
Diluted earnings per share (in dollars per shares)	$ 47.14	$ 30.11	$ 15.51
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
Weighted average common shares outstanding basic (in shares)	15,441,292	17,655,365	17,754,666
Weighted average common shares outstanding diluted (in shares)	15,493,616	17,722,212	17,806,578
New vehicle retail sales
REVENUES	$ 7,452.5	$ 6,504.8	$ 5,428.4
COST OF SALES	6,627.0	5,894.0	5,109.1
Used vehicle retail sales
REVENUES	5,673.3	4,438.8	3,055.6
COST OF SALES	5,359.6	4,084.6	2,850.7
Used vehicle wholesale sales
REVENUES	364.6	365.7	295.8
COST OF SALES	364.6	340.9	285.6
Parts and service sales
REVENUES	2,009.5	1,591.2	1,357.4
COST OF SALES	905.8	721.8	620.8
Finance, insurance and other, net
REVENUES	$ 722.2	$ 581.4	$ 463.0