Acquisitions - Assets (Liabilities) Acquired (Assumed) at Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Tangible assets (liabilities) acquired (assumed):
Goodwill	$ 506,954		$ 483,634
Cash paid for acquisitions, net of cash acquired	34,808	$ 10,406
2022 Acquisitions
Tangible assets (liabilities) acquired (assumed):
Inventories, net	11,425
Prepaid expenses and other assets	13
Property and equipment, net	70
Accrued liabilities	(20)
Total tangible net assets acquired	11,488
Goodwill	23,320
Cash paid for acquisitions, net of cash acquired	34,808
Inventory purchases financed via floor plan	(5,876)
Cash payment net of floor plan financing	$ 28,932
2021 Acquisitions
Tangible assets (liabilities) acquired (assumed):
Inventories, net		3,318
Prepaid expenses and other assets		0
Property and equipment, net		188
Accrued liabilities		(112)
Total tangible net assets acquired		3,394
Goodwill		7,012
Cash paid for acquisitions, net of cash acquired		10,406
Inventory purchases financed via floor plan		0
Cash payment net of floor plan financing		$ 10,406