Revenue (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($) segment	Sep. 30, 2021 USD ($) segment	Sep. 30, 2022 USD ($) segment	Sep. 30, 2021 USD ($) segment
Disaggregation of Revenue [Line Items]
Contract revenues	$ 182,621	$ 139,907	$ 552,127	$ 439,091
Number of reportable segments | segment	2	2	2	2
Marine Segment
Disaggregation of Revenue [Line Items]
Contract revenues	$ 76,098	$ 54,739	$ 242,897	$ 190,827
Marine Segment | Construction
Disaggregation of Revenue [Line Items]
Contract revenues	56,765	38,883	169,127	121,678
Marine Segment | Dredging
Disaggregation of Revenue [Line Items]
Contract revenues	17,408	13,157	63,894	58,511
Marine Segment | Specialty Services
Disaggregation of Revenue [Line Items]
Contract revenues	1,925	2,699	9,876	10,638
Concrete Segment
Disaggregation of Revenue [Line Items]
Contract revenues	106,523	85,168	309,230	248,264
Concrete Segment | Structural
Disaggregation of Revenue [Line Items]
Contract revenues	15,070	13,090	46,610	47,296
Concrete Segment | Light Commercial
Disaggregation of Revenue [Line Items]
Contract revenues	$ 91,453	$ 72,078	$ 262,620	200,961
Concrete Segment | Other
Disaggregation of Revenue [Line Items]
Contract revenues				$ 7