Note 5 - Supplemental Balance Sheet Information - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Vendor and other accrued expenses	$ 17,152	$ 26,313
Estimated casualty and healthcare liabilities	10,624	10,702
Job costs	13,416	12,041
Accrued compensation	17,112	17,045
Income taxes payable	1,360	1,751
Total	$ 59,664	$ 67,852