Revenue (Tables)

6 Months Ended

Jun. 30, 2020

Revenue from Contract with Customer [Abstract]

Schedule of disaggregation of revenue

	Three months ended June 30,				Six months ended June 30,
	2020		2019		2020		2019
Marine Segment
Construction	$	65,814	$	57,181	$	118,954	$	90,817
Dredging		24,230		27,191		55,129		53,358
Specialty Services		1,675		4,651		3,585		6,335
Marine segment contract revenues	$	91,719	$	89,023	$	177,668	$	150,510
Concrete Segment
Structural	$	24,541	$	12,665	$	45,777	$	24,156
Light Commercial		67,442		64,275		126,875		134,371
Other		11		22		13		53
Concrete segment contract revenues	$	91,994	$	76,962	$	172,665	$	158,580
Total contract revenues	$	183,713	$	165,985	$	350,333	$	309,090