Revenue (Tables)

12 Months Ended

Dec. 31, 2020

Revenue from Contract with Customer [Abstract]

Schedule of disaggregation of revenue

	Year ended December 31,
	2020		2019		2018
Marine Segment
Construction	$	272,870	$	242,527	$	156,925
Dredging		106,647		112,303		73,237
Specialty Services		8,656		14,308		13,721
Marine segment contract revenues	$	388,173	$	369,138	$	243,883
Concrete Segment
Structural	$	85,904	$	54,497	$	60,926
Light Commercial		235,835		284,624		215,628
Other		30		131		457
Concrete segment contract revenues	$	321,769	$	339,252	$	277,011
Total contract revenues	$	709,942	$	708,390	$	520,894