Note 3 - Supplier Concentration (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Oct. 01, 2021	Sep. 14, 2021
Line of Credit Facility, Maximum Borrowing Capacity	$ 15
BMO Harris Bank N.A. [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,000
WF Lenders [Member] | Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity					$ 250
PLC Agreement [Member] | Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity				$ 300
Product Concentration Risk [Member] | Revenue Benchmark [Member] | Sales of New Peterbilt Commercial Vehicles [Member]
Concentration Risk, Percentage	62.50%	59.00%	61.60%