Inventories and Floor Plan Payables - Floor Plan Outstanding (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2025	Feb. 28, 2025	Dec. 31, 2024	Jun. 30, 2024
Minimum
Notes payable - floor plan:
Floor plan payment due period	3 days
Maximum
Notes payable - floor plan:
Floor plan payment due period	10 days
Floor Plan Facility
Notes payable - floor plan:
Total commitment	$ 2,150,000	$ 2,150,000	$ 1,850,000	$ 1,850,000
Less: borrowings	(1,280,102)		(1,161,713)	(1,296,352)
Less: FLAIR offset account	(39)		(79,472)	(199,522)
Additional borrowing capacity	869,859		608,815	354,126
Less: short-term payable for sold inventory	(82,871)		(33,152)	(97,209)
Less: purchase commitments	(26,884)		(9,340)	(31,382)
Unencumbered borrowing capacity	760,104		566,323	225,535
Line of Credit | Floor Plan Facility
Notes payable - floor plan:
Total commitment	70,000		70,000	70,000
Less: borrowings				(31,885)
Additional borrowing capacity	70,000		70,000	38,115
Letters of credit | Floor Plan Facility
Notes payable - floor plan:
Total commitment	45,000	$ 45,000	30,000	30,000
Less: outstanding letters of credit	(14,300)		(14,300)	(12,300)
Additional letters of credit capacity	$ 30,700		$ 15,700	$ 17,700