Note 15 - Acquisitions (Details Textual) - USD ($) $ in Thousands				12 Months Ended
	Dec. 13, 2021	Nov. 01, 2021	Oct. 18, 2021	Dec. 31, 2021	Dec. 31, 2019	Dec. 31, 2020
Payments to Acquire Businesses, Gross				$ 269,332	$ 10,168
Goodwill, Ending Balance				370,331	$ 292,142	$ 292,142
Asset Purchase Agreement With Summit [Member]
Business Combination, Consideration Transferred, Total	$ 205,300
Business Combination, Consideration Transferred, Liabilities Incurred	102,000
Payments to Acquire Real Estate, Total	$ 57,000
Goodwill, Ending Balance				$ 73,710
Illinois Truck Centre, Inc. [Member]
Payments to Acquire Businesses, Gross		$ 2,700
Goodwill, Ending Balance		$ 1,000
Commercial Engine Service, Inc. [Member]
Payments to Acquire Businesses, Gross			$ 4,300
Goodwill, Ending Balance			$ 3,500