Credit Facilities and Long-term Debt - Schedule of Credit Facilities and Long-term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Finance lease obligations	$ 56.4	$ 53.6
Less: current maturities (net of current debt issuance costs)	(20.5)	(223.7)
Line of credit
Debt Instrument [Line Items]
Long-term debt, gross	2,734.8	719.9
Line of credit \| Used and service loaner vehicle inventory financing commitments
Debt Instrument [Line Items]
Long-term debt, gross	877.2	500.0
Line of credit \| Revolving lines of credit
Debt Instrument [Line Items]
Long-term debt, gross	927.6	129.9
Line of credit \| Warehouse facilities
Debt Instrument [Line Items]
Long-term debt, gross	930.0	90.0
Real estate mortgages
Debt Instrument [Line Items]
Long-term debt, gross	580.1	592.9
Senior notes \| 4.625% Senior notes due 2027
Debt Instrument [Line Items]
Long-term debt, gross	$ 400.0	400.0
Debt stated interest rate	4.625%
Senior notes \| 4.375% Senior notes due 2031
Debt Instrument [Line Items]
Long-term debt, gross	$ 550.0	550.0
Debt stated interest rate	4.375%
Senior notes \| 3.875% Senior notes due 2029
Debt Instrument [Line Items]
Long-term debt, gross	$ 800.0	800.0
Debt stated interest rate	3.875%
Other debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 16.6	1.9
Long-term debt excluding notes payable
Debt Instrument [Line Items]
Total long-term debt outstanding	5,137.9	3,118.3
Less: unamortized debt issuance costs	(29.1)	(26.5)
Less: current maturities (net of current debt issuance costs)	(20.5)	(223.7)
Long-term debt, less current maturities	5,088.3	2,868.1
Notes payable
Debt Instrument [Line Items]
Long-term debt, less current maturities	422.2	317.6
Notes payable \| Nonrecourse
Debt Instrument [Line Items]
Long-term Debt	$ 422.2	$ 317.6

Long-Term Debt, Gross And Lease Obligation

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Present value of lessee's discounted obligation for lease payments from finance lease.

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