Note 7 - Long-term Debt - Summary of Long-term Debt (Details) - USD ($) $ in Thousands		Dec. 31, 2021	Dec. 31, 2020
Long-term debt		$ 222,277	$ 286,106
Less current maturities		(49,544)	(57,776)
Long-term debt—net of current maturities		172,733	228,330
Line of Credit [Member]
Long-term debt	[1]	0	18,246
Secured Debt [Member]
Long-term debt	[2]	206,539	250,572
Texas Real Estate Agreement [Member]
Long-term debt	[3]	$ 15,738
Real Estate Financing [Member]
Long-term debt	[3]		$ 17,288

[1] Line of credit agreement with a bank provides for maximum borrowings of $60.0 million and contains certain restrictive covenants that must be maintained by the Company on a consolidated basis. Borrowings on the line of credit are at an interest rate of LIBOR as of the first day of the month (with a floor of 0.5%) plus 1.25%, (1.75% at December 31, 2021) and are secured by our trade accounts receivable. An “unused fee” of 0.25% is charged if average daily borrowings are less than $18.0 million in a given month. Monthly payments of interest are required under this agreement. Also, under the terms of the agreement the Company must maintain a debt to adjusted EBITDA (earnings before interest, taxes, depreciation, and amortization, excluding gains/losses on equity securities and extraordinary items) ratio of less than 4.00:1. The Company was in compliance with all provisions under this agreement throughout 2021. At December 31, 2021, outstanding advances on the line were approximately $0.4 million, including letters of credit totaling $0.3 million, with availability to borrow $59.6 million. At December 31, 2020, outstanding advances on the line were approximately $18.6 million, including letters of credit totaling $0.3 million.

[2] Equipment financings consist of installment obligations for revenue equipment purchases, payable in various monthly installments with various maturity dates through March 2028, at a weighted average interest rate of 2.81% as of December 31, 2021 and collateralized by revenue equipment.

[3] Real estate financing consisting of an installment obligation for the purchase of real estate in Laredo, TX, payable in 120 installments at an interest rate of 3.02% and maturing in August 2030. This obligation is collateralized by the underlying real estate and any rental income generated by the underlying real estate.