Segment Information (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	Dec. 31, 2021 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	2	2	2	2
Contract revenues	$ 182,621	$ 139,907	$ 552,127	$ 439,091
Operating income (loss)	1,131	(8,743)	(4,572)	(1,122)
Depreciation and amortization			(16,035)	(16,881)
Assets	348,156		348,156		$ 351,750
Property and equipment, net	101,774		101,774		$ 106,654
Marine Segment
Segment Reporting Information [Line Items]
Contract revenues	76,098	54,739	242,897	190,827
Marine Segment | Mexico and the Caribbean
Segment Reporting Information [Line Items]
Contract revenues	2,500		5,100	2,800
Marine Segment | Mexico and the Caribbean | Maximum
Segment Reporting Information [Line Items]
Contract revenues		100
Concrete Segment
Segment Reporting Information [Line Items]
Contract revenues	106,523	85,168	309,230	248,264
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	76,098	54,739	242,897	190,827
Operating income (loss)	5,197	(4,965)	9,553	6,489
Depreciation and amortization	(4,192)	(4,232)	(12,751)	(12,912)
Assets	219,955	252,332	219,955	252,332
Property and equipment, net	91,338	92,612	91,338	92,612
Operating Segments | Concrete Segment
Segment Reporting Information [Line Items]
Contract revenues	106,523	85,168	309,230	248,264
Operating income (loss)	(4,066)	(3,778)	(14,125)	(7,611)
Depreciation and amortization	(1,873)	(1,993)	(5,675)	(6,228)
Assets	128,201	116,023	128,201	116,023
Property and equipment, net	10,436	14,073	10,436	14,073
Intersegment Eliminations
Segment Reporting Information [Line Items]
Contract revenues		$ 0	$ 100
Intersegment Eliminations | Maximum
Segment Reporting Information [Line Items]
Contract revenues	$ 100			$ 100