Segment Reporting (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2016 USD ($) segment	Mar. 31, 2015 USD ($) segment	Dec. 31, 2015 segment
Segment Reporting Information [Line Items]
Number of reportable segments (segment) | segment	2	1	1
Contract revenues	$ 129,623,000	$ 81,455,000
Heavy Civil Marine Construction | Mexico and the Caribbean
Segment Reporting Information [Line Items]
Contract revenues	2,400,000	7,300,000
Intersegment Eliminations
Segment Reporting Information [Line Items]
Contract revenues	$ 0	$ 0