Note 2 - Details of Consolidated Balance Sheet Accounts - Prepaid Expenses and Other (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Insurance premiums	$ 3,749	$ 3,653
Contract assets	2,243	1,545
Other	3,504	3,103
Prepaid Expense and Other Assets, Current	23,980	21,903
License Fees Member [Member]
Prepaid expenses	5,485	5,529
Tires In Service [Member]
Prepaid expenses	4,624	4,701
Parts And Tires Inventory [Member]
Prepaid expenses	$ 4,375	$ 3,372