Revenue (Tables)

6 Months Ended

Jun. 30, 2021

Revenue from Contract with Customer [Abstract]

Schedule of disaggregation of revenue

	Three months ended June 30,				Six months ended June 30,
	2021		2020		2021		2020
Marine Segment
Construction	$	38,859	$	65,814	$	82,795	$	118,954
Dredging		20,672		24,230		45,354		55,129
Specialty Services		4,411		1,675		7,939		3,585
Marine segment contract revenues	$	63,942	$	91,719	$	136,088	$	177,668
Concrete Segment
Structural	$	17,545	$	24,541	$	34,206	$	45,777
Light Commercial		64,388		67,442		128,883		126,875
Other		—		11		7		13
Concrete segment contract revenues	$	81,933	$	91,994	$	163,096	$	172,665
Total contract revenues	$	145,875	$	183,713	$	299,184	$	350,333