Segment Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) segment	Mar. 31, 2023 USD ($) segment	Dec. 31, 2023 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	2	2
Contract revenues	$ 160,672	$ 159,174
Operating income (loss)	(3,124)	(10,643)
Depreciation and amortization	(4,208)	(4,721)
Assets	363,584		$ 416,893
Property and equipment, net of depreciation	85,473		$ 87,834
Marine Segment
Segment Reporting Information [Line Items]
Contract revenues	106,325	79,298
Marine Segment | Foreign
Segment Reporting Information [Line Items]
Contract revenues	9,600	2,800
Concrete Segment
Segment Reporting Information [Line Items]
Contract revenues	54,347	79,876
Concrete Segment | Foreign
Segment Reporting Information [Line Items]
Contract revenues	0	0
Operating Segments | Marine Segment
Segment Reporting Information [Line Items]
Contract revenues	106,325	79,298
Operating income (loss)	(4,866)	(6,080)
Depreciation and amortization	(4,931)	(3,835)
Assets	275,969	231,851
Property and equipment, net of depreciation	80,261	88,957
Operating Segments | Concrete Segment
Segment Reporting Information [Line Items]
Contract revenues	54,347	79,876
Operating income (loss)	1,742	(4,563)
Depreciation and amortization	(1,089)	(1,611)
Assets	87,615	112,336
Property and equipment, net of depreciation	5,212	8,350
Intersegment Eliminations
Segment Reporting Information [Line Items]
Contract revenues	$ 600
Intersegment Eliminations | Maximum
Segment Reporting Information [Line Items]
Contract revenues		$ 100