Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) segment	Sep. 30, 2022 USD ($) segment	Sep. 30, 2023 USD ($) segment	Sep. 30, 2022 USD ($) segment	Dec. 31, 2022 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	2	2	2	2
Contract revenues	$ 168,476	$ 182,621	$ 510,184	$ 552,127
Operating income (loss)	2,561	1,131	(6,043)	(4,572)
Depreciation and amortization			(13,874)	(16,035)
Assets	380,222		380,222		$ 367,155
Property and equipment, net of depreciation	89,585		89,585		$ 100,977
Marine Segment
Segment Reporting Information [Line Items]
Contract revenues	80,913	76,098	260,754	242,897
Marine Segment | Foreign
Segment Reporting Information [Line Items]
Contract revenues	4,500	2,500	14,500	5,100
Concrete Segment
Segment Reporting Information [Line Items]
Contract revenues	87,563	106,523	249,430	309,230
Concrete Segment | Foreign
Segment Reporting Information [Line Items]
Contract revenues	0	0	0	0
Operating Segments | Marine Segment
Segment Reporting Information [Line Items]
Contract revenues	80,913	76,098	260,754	242,897
Operating income (loss)	2,001	5,197	(587)	9,553
Depreciation and amortization	(4,771)	(4,192)	(12,418)	(12,751)
Assets	269,409	219,955	269,409	219,955
Property and equipment, net of depreciation	82,914	91,338	82,914	91,338
Operating Segments | Concrete Segment
Segment Reporting Information [Line Items]
Contract revenues	87,563	106,523	249,430	309,230
Operating income (loss)	560	(4,066)	(5,456)	(14,125)
Depreciation and amortization	(1,322)	(1,873)	(4,464)	(5,675)
Assets	110,813	128,201	110,813	128,201
Property and equipment, net of depreciation	6,671	10,436	6,671	10,436
Intersegment Eliminations
Segment Reporting Information [Line Items]
Contract revenues	$ 100		$ 100	$ 100
Intersegment Eliminations | Maximum
Segment Reporting Information [Line Items]
Contract revenues		$ 100