Revenue (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) segment	Dec. 31, 2020 USD ($) segment	Dec. 31, 2019 USD ($) segment
Disaggregation of Revenue [Line Items]
Contract revenues	$ 601,360	$ 709,942	$ 708,390
Number of reportable segments | segment	2	2	2
Marine Segment
Disaggregation of Revenue [Line Items]
Contract revenues	$ 263,915	$ 388,173	$ 369,138
Marine Segment | Construction
Disaggregation of Revenue [Line Items]
Contract revenues	169,554	272,870	242,527
Marine Segment | Dredging
Disaggregation of Revenue [Line Items]
Contract revenues	80,831	106,647	112,303
Marine Segment | Specialty Services
Disaggregation of Revenue [Line Items]
Contract revenues	13,530	8,656	14,308
Concrete Segment
Disaggregation of Revenue [Line Items]
Contract revenues	337,445	321,769	339,252
Concrete Segment | Structural
Disaggregation of Revenue [Line Items]
Contract revenues	58,420	85,904	54,497
Concrete Segment | Light Commercial
Disaggregation of Revenue [Line Items]
Contract revenues	279,018	235,835	284,624
Concrete Segment | Other
Disaggregation of Revenue [Line Items]
Contract revenues	$ 7	$ 30	$ 131