Segment Information (Tables)

12 Months Ended

Dec. 31, 2016

Segment Reporting [Abstract]

Segment Reporting By Segment

	2016			2015			2014
Dredging:
Contract revenues	$	637,468		$	681,255		$	697,711
Operating income		34,108			64,073			41,620
Depreciation and amortization		54,826			50,556			43,620
Total assets		912,880			872,297			812,181
Property and equipment—net		399,479			397,468			366,027
Goodwill		76,576			76,576			76,576
Investment in joint ventures		381			1			2,114
Capital expenditures		84,263			82,000			79,186
Environmental & infrastructure:
Contract revenues		133,637			181,710			114,412
Operating loss		(19,428	)		(41,114	)		(17,767	)
Depreciation and amortization		8,197			14,029			6,509
Total assets		81,166			127,907			134,324
Property and equipment—net		13,529			32,742			33,418
Goodwill		7,000			7,000			9,750
Investment in joint ventures		4,353			3,760			5,775
Capital expenditures		949			7,279			12,892
Intersegment:
Contract revenues		(3,520	)		(6,087	)		(5,292	)
Total assets		(100,458	)		(102,080	)		(56,773	)
Total:
Contract revenues		767,585			856,878			806,831
Operating income		14,680			22,959			23,853
Depreciation and amortization		63,023			64,585			50,129
Total assets		893,588			898,124			889,732
Property and equipment—net		413,008			430,210			399,445
Goodwill		83,576			83,576			86,326
Investment in joint ventures		4,734			3,761			7,889
Capital expenditures		85,212			89,279			92,078

Revenue Related to Dredging Projects By Type Of Work

	2016		2015		2014
Capital dredging — U.S.	$	219,914	$	207,058	$	195,635
Capital dredging — foreign		59,413		139,945		155,000
Coastal protection dredging		215,041		184,060		194,219
Maintenance dredging		92,274		120,055		123,923
Rivers & lakes		50,826		30,137		28,934
Total dredging	$	637,468	$	681,255	$	697,711

Revenues And Gross Profit From Foreign Project Operations

	2016			2015			2014
Contract revenues	$	59,413		$	139,945		$	155,000
Costs of contract revenues		(66,729	)		(105,951	)		(118,682	)
Gross profit	$	(7,316	)	$	33,994		$	36,318