Receivables, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Affirmative Claim Recovery Estimate	$ 12,500	$ 12,300	$ 12,400
Total Gross Receivables	351,565	419,918	307,801
Allowance for Accounts, Notes, Loans and Financing Receivable, Current	474	573	318
Receivables, net	351,091	419,345	307,483
Back charges claims	300	300	7,000
Construction Contract [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Gross Receivables	310,006	373,038	272,469
Completed and in Progress [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Gross Receivables	227,314	288,160	178,974
Retentions [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Gross Receivables	82,692	84,878	93,495
Construction Material Sales [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Gross Receivables	25,582	29,357	23,392
Other Business Products and Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Gross Receivables	$ 15,977	$ 17,523	$ 11,940