Revenue (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($) segment	Jun. 30, 2023 USD ($) segment	Jun. 30, 2024 USD ($) segment	Jun. 30, 2023 USD ($) segment
Disaggregation of Revenue [Line Items]
Contract revenues	$ 192,167	$ 182,534	$ 352,839	$ 341,708
Number of reportable segments | segment	2	2	2	2
Marine
Disaggregation of Revenue [Line Items]
Contract revenues	$ 130,953	$ 100,543	$ 237,278	$ 179,841
Marine | Construction
Disaggregation of Revenue [Line Items]
Contract revenues	116,025	77,721	204,814	131,733
Marine | Dredging
Disaggregation of Revenue [Line Items]
Contract revenues	12,077	14,819	26,747	35,549
Marine | Specialty Services
Disaggregation of Revenue [Line Items]
Contract revenues	2,851	8,003	5,717	12,559
Concrete
Disaggregation of Revenue [Line Items]
Contract revenues	61,214	81,991	115,561	161,867
Concrete | Structural
Disaggregation of Revenue [Line Items]
Contract revenues	16,895	13,837	28,468	29,581
Concrete | Light Commercial
Disaggregation of Revenue [Line Items]
Contract revenues	$ 44,319	$ 68,154	$ 87,093	$ 132,286