Revenue (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($) segment	Sep. 30, 2023 USD ($) segment	Sep. 30, 2024 USD ($) segment	Sep. 30, 2023 USD ($) segment
Disaggregation of Revenue [Line Items]
Contract revenues	$ 226,675	$ 168,476	$ 579,514	$ 510,184
Number of reportable segments | segment	2	2	2	2
Marine
Disaggregation of Revenue [Line Items]
Contract revenues	$ 140,013	$ 80,913	$ 377,291	$ 260,754
Marine | Construction
Disaggregation of Revenue [Line Items]
Contract revenues	123,141	58,162	327,955	189,895
Marine | Dredging
Disaggregation of Revenue [Line Items]
Contract revenues	12,902	9,444	39,649	44,993
Marine | Specialty Services
Disaggregation of Revenue [Line Items]
Contract revenues	3,970	13,307	9,687	25,866
Concrete
Disaggregation of Revenue [Line Items]
Contract revenues	86,662	87,563	202,223	249,430
Concrete | Structural
Disaggregation of Revenue [Line Items]
Contract revenues	15,572	12,268	44,040	41,849
Concrete | Light Commercial
Disaggregation of Revenue [Line Items]
Contract revenues	$ 71,090	$ 75,295	$ 158,183	$ 207,581