Acquisitions - Assets (Liabilities) Acquired (Assumed) at Fair Value (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024	Dec. 31, 2023
Tangible assets (liabilities) acquired (assumed):
Goodwill	$ 748,951	$ 732,813	$ 734,023	$ 711,222
Application of deposit paid in prior period	(11,000)	(8,873)
Cash paid for acquisitions, net of cash acquired	81,203	62,323
2025 Acquisitions
Tangible assets (liabilities) acquired (assumed):
Accounts receivable, net	0
Inventories, net	73,002
Prepaid expenses and other assets	58
Property and equipment, net	1,414
Operating lease assets	9,366
Accounts payable	0
Accrued liabilities	(140)
Current portion of operating lease liabilities	(1,055)
Other current liabilities	(471)
Operating lease liabilities, net of current portion	(8,312)
Total tangible net assets acquired	73,862
Total intangible assets acquired	0
Goodwill	18,341
Purchase price of acquisitions	92,203
Application of deposit paid in prior period	(11,000)
Contingent consideration	0
Cash paid for acquisitions, net of cash acquired	81,203
Inventory purchases financed via floor plan	(71,181)
Cash payment net of floor plan financing	10,022
2025 Acquisitions | Supplier and customer relationships
Tangible assets (liabilities) acquired (assumed):
Total intangible assets acquired	0
2025 Acquisitions | Websites and developed technology
Tangible assets (liabilities) acquired (assumed):
Total intangible assets acquired	$ 0
2024 Acquisitions
Tangible assets (liabilities) acquired (assumed):
Accounts receivable, net		4
Inventories, net		37,642
Prepaid expenses and other assets		0
Property and equipment, net		296
Operating lease assets		15,328
Accounts payable		(5)
Accrued liabilities		(35)
Current portion of operating lease liabilities		(1,112)
Other current liabilities		(23)
Operating lease liabilities, net of current portion		(14,216)
Total tangible net assets acquired		37,879
Total intangible assets acquired		3,195
Goodwill		30,490
Purchase price of acquisitions		71,564
Application of deposit paid in prior period		(8,873)
Contingent consideration		(368)
Cash paid for acquisitions, net of cash acquired		62,323
Inventory purchases financed via floor plan		(49,162)
Cash payment net of floor plan financing		13,161
2024 Acquisitions | Supplier and customer relationships
Tangible assets (liabilities) acquired (assumed):
Total intangible assets acquired		2,595
2024 Acquisitions | Websites and developed technology
Tangible assets (liabilities) acquired (assumed):
Total intangible assets acquired		$ 600