Note 8 - Contract Assets and Liabilities - Component of Contract Asset and Liability Balances (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Costs in excess of billings and estimated earnings	$ 73,745	$ 100,761	$ 128,239
Contract retention	118,174	110,680	96,150
Total contract assets	191,919	211,441	224,389
Billings in excess of costs and estimated earnings, net of retention	148,050	86,736	119,881
Provisions for losses	11,768	9,001	8,562
Total contract liabilities	$ 159,818	$ 95,737	$ 128,443