Revenue (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2025 USD ($) segment	Dec. 31, 2024 USD ($) segment	Dec. 31, 2023 USD ($) segment
Disaggregation of Revenue [Line Items]
Contract revenues	$ 852,260	$ 796,394	$ 711,778
Number of reportable segments | segment	2	2	2
Marine
Disaggregation of Revenue [Line Items]
Contract revenues	$ 544,831	$ 521,250	$ 395,917
Marine | Construction
Disaggregation of Revenue [Line Items]
Contract revenues	453,170	448,321	297,462
Marine | Dredging
Disaggregation of Revenue [Line Items]
Contract revenues	76,429	57,048	60,667
Marine | Specialty Services
Disaggregation of Revenue [Line Items]
Contract revenues	15,232	15,881	37,788
Concrete
Disaggregation of Revenue [Line Items]
Contract revenues	307,429	275,144	315,861
Concrete | Structural
Disaggregation of Revenue [Line Items]
Contract revenues	45,819	61,545	53,827
Concrete | Light Commercial
Disaggregation of Revenue [Line Items]
Contract revenues	$ 261,610	$ 213,599	$ 262,034