Organization and Summary of Significant Accounting Policies - Impairment Testing (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) reporting segment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	4
Goodwill	$ 2,154,700,000	$ 2,124,100,000	$ 1,928,400,000
Retail automotive dealership
Segment Reporting Information [Line Items]
Number of reportable segments | segment	1
Number of operating segments | reporting	6
Goodwill	$ 1,617,600,000	1,622,200,000	1,534,800,000
Retail commercial truck dealership
Segment Reporting Information [Line Items]
Number of operating segments and reporting units for the purpose of goodwill impairment testing | segment	1
Goodwill	$ 462,300,000	$ 422,300,000	$ 309,400,000
Non-Automotive Investments
Segment Reporting Information [Line Items]
Goodwill	$ 0