Concentration of Risk and Enterprise Wide Disclosures (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended	12 Months Ended	3 Months Ended		9 Months Ended		1 Months Ended	12 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended			9 Months Ended	1 Months Ended		12 Months Ended	3 Months Ended	9 Months Ended		12 Months Ended	3 Months Ended		9 Months Ended			12 Months Ended	3 Months Ended		9 Months Ended			12 Months Ended	3 Months Ended		9 Months Ended			12 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Trade and Contract Retainage Receivables [Member]	Dec. 31, 2011 Customer Concentration Risk [Member] Trade and Contract Retainage Receivables [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] US Army Corps of Engineers [Member] Trade and Contract Retainage Receivables [Member]	Dec. 31, 2011 Customer Concentration Risk [Member] US Army Corps of Engineers [Member] Trade and Contract Retainage Receivables [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] US Army Corps of Engineers [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] US Army Corps of Engineers [Member] Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] US Army Corps of Engineers [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] US Army Corps of Engineers [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] U.S. Navy [Member] [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] Florida Department of Transportation [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] Louisiana Department of Transportation [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] Louisiana Department of Transportation [Member] Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Canaveral Port Authority [Member] Trade and Contract Retainage Receivables [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Private Sector Customer [Member] Trade and Contract Retainage Receivables [Member]	Dec. 31, 2011 Customer Concentration Risk [Member] Private Sector Customer [Member] Trade and Contract Retainage Receivables [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Private Sector Customer [Member] Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Private Sector Customer [Member] Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Federal Government [Member] Trade and Contract Retainage Receivables [Member]	Dec. 31, 2011 Customer Concentration Risk [Member] Federal Government [Member] Trade and Contract Retainage Receivables [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Federal Government [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] Federal Government [Member] Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Federal Government [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] Federal Government [Member] Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] State Governments [Member] Trade and Contract Retainage Receivables [Member]	Dec. 31, 2011 Customer Concentration Risk [Member] State Governments [Member] Trade and Contract Retainage Receivables [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] State Governments [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] State Governments [Member] Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] State Governments [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] State Governments [Member] Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Local Governments [Member] Trade and Contract Retainage Receivables [Member]	Dec. 31, 2011 Customer Concentration Risk [Member] Local Governments [Member] Trade and Contract Retainage Receivables [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Local Governments [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] Local Governments [Member] Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Local Governments [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] Local Governments [Member] Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Private Companies [Member] Trade and Contract Retainage Receivables [Member]	Dec. 31, 2011 Customer Concentration Risk [Member] Private Companies [Member] Trade and Contract Retainage Receivables [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Private Companies [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] Private Companies [Member] Contract Revenues [Member]	Sep. 30, 2012 Customer Concentration Risk [Member] Private Companies [Member] Contract Revenues [Member]	Sep. 30, 2011 Customer Concentration Risk [Member] Private Companies [Member] Contract Revenues [Member]
Concentration Risk [Line Items]
Trade and retainage receivables						$ 39,129	$ 26,931																				$ 6,181	$ 5,958					$ 1,400	$ 379					$ 4,455	$ 6,207					$ 27,093	$ 14,387
Concentration risk, percentage						100.00%	100.00%	100.00%	100.00%	100.00%	100.00%	12.00%	9.10%	19.50%	26.10%	16.80%	24.60%	11.90%	13.40%	11.50%	12.90%	11.00%	21.70%	12.50%	11.50%	12.60%	16.00%	22.00%	23.00%	44.00%	22.00%	45.00%	4.00%	1.00%	15.00%	18.00%	15.00%	20.00%	11.00%	24.00%	10.00%	23.00%	17.00%	17.00%	69.00%	53.00%	52.00%	15.00%	47.00%	18.00%
Contract revenues	$ 75,386	$ 54,583	$ 193,408	$ 204,539	$ 75,386				$ 54,583	$ 193,408	$ 204,539																		$ 17,408	$ 24,175	$ 42,336	$ 91,377			$ 11,623	$ 9,559	$ 28,637	$ 41,631			$ 7,463	$ 12,644	$ 32,057	$ 34,820			$ 38,892	$ 8,205	$ 90,378	$ 36,711