Note 2 - Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues	$ 54,614	$ 46,138	$ 158,174	$ 128,967
Consolidation, Eliminations [Member]
Revenues	(32)	(2)	(39)	(2)
Heavy Fabrications [Member] | Operating Segments [Member]
Revenues	43,440	33,834	125,424	91,098
Gearing [Member] | Operating Segments [Member]
Revenues	7,125	7,989	20,273	27,282
Industrial Solutions [Member] | Operating Segments [Member]
Revenues	$ 4,081	$ 4,317	$ 12,516	$ 10,589