Segment Reporting - Summary (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Contract revenues	$ 129,623	$ 81,455
Operating loss	(827)	(236)
Depreciation and amortization expense	(8,550)	(5,445)
Total Assets	452,279		$ 461,462
Property and equipment, net	166,011		$ 165,989
Operating Segments | Heavy Civil Marine Construction
Segment Reporting Information [Line Items]
Contract revenues	62,415	81,455
Operating loss	(1,068)	1,847
Depreciation and amortization expense	(5,067)	(5,445)
Total Assets	305,270	339,946
Property and equipment, net	150,978	162,057
Operating Segments | Commercial Concrete Construction
Segment Reporting Information [Line Items]
Contract revenues	67,208	0
Operating loss	241	0
Depreciation and amortization expense	(3,483)	0
Total Assets	147,009	0
Property and equipment, net	$ 15,033	$ 0