Receivables, Net - Summary of Receivables (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Gross Receivables	$ 330,297	$ 479,943	$ 351,565
Less: allowance for doubtful accounts	105	152	474
Total net receivables	330,192	479,791	351,091
Completed and in Progress [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Gross Receivables	287,622	420,737	310,006
Construction Material Sales [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Gross Receivables	28,233	42,192	25,582
Other Business Products and Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Gross Receivables	14,442	17,014	15,977
Billed [Member] | Completed and in Progress [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Gross Receivables	214,494	252,467	142,216
Unbilled Revenues | Completed and in Progress [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Gross Receivables	$ 73,128	77,135	85,098
Retentions [Member] | Completed and in Progress [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Gross Receivables		$ 91,135	$ 82,692