Note 4 - Revisions in Estimates - Summary of Impact of Revisions in Estimates to Gross Profit (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($) $ / shares	Mar. 31, 2020 USD ($) $ / shares
Gross Profit, Total	$ 63,318	$ 23,799
Diluted (in dollars per share) | $ / shares	$ (1.45)	$ (1.44)
Estimated Cost Recovery of Customer Affirmative Claims and Back Charges [Member]
Number of projects with downward estimate changes	1	2
Gross Profit, Total	$ 5,300
Increase to net loss	$ 4,100	$ 21,600
Diluted (in dollars per share) | $ / shares	$ 0.09	$ 0.47
Estimated Cost Recovery of Customer Affirmative Claims and Back Charges [Member] | Minimum [Member]
Gross Profit, Total		$ 5,800
Estimated Cost Recovery of Customer Affirmative Claims and Back Charges [Member] | Maximum [Member]
Gross Profit, Total		$ 22,700