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Note 1 - Summary of Business and Significant Accounting Policies (Details Textual) - USD ($) $ / shares in Units, $ in Thousands | 1 Months Ended | 12 Months Ended
--- | --- | ---
Aug. 31, 2015 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Ownership Interest in Joint Venture |  | 50.00% |  |
Estimated Construction Gross Profit (Loss) Per Diluted Share |  | $ 0.27 | $ 0.50 | $ 0.50
Proceeds from Sale of Long-term Contract | $ 7,100 |  |  |
Contract Receivable |  |  | $ 0 |
Notes Payable, Noncurrent |  | $ 2,700 |  |
Contract Receivable Retainage |  | 23,400 | 19,800 |
Unbilled Contracts Receivable |  | 0 | 0 |
Interest Income from Contracts Receivable |  |  | 200 | $ 400
Allowance for Doubtful Accounts Receivable, Write-offs |  | 0 | 0 | 0
Inventory, Net |  | 3,708 | 2,535 |
Depreciation |  | 15,700 | 16,200 | 18,200
Capitalized Debt Fees |  |  | 1,300 |
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums |  | 800 | 1,100 |
Amortization of Debt Issuance Costs |  | 300 | 300 | 200
Impairment of Long-Lived Assets Held-for-use |  | $ 0 | 0 | 0
Number of Operating Segments |  | 1 |  |
Number of Reportable Segments |  | 1 |  |
Number of Reporting Units |  | 1 |  |
Long-term Contract Receivable [Member] |  |  |  |
Fair Value Inputs, Discount Rate |  | 4.25% |  |
Costs and Estimated Earnings in Excess of Billings [Member] |  |  |  |
Unapproved Change Orders, Amount |  | $ 2,200 | 1,600 |
Contracts Receivable, Claims and Uncertain Amounts |  | 9,200 | 5,200 |
Contracts Receivable, Unpaid Project Contract Price |  | 3,900 | 3,900 |
Other Noncurrent Liabilities [Member] | JBC Former Owners [Member] | Fair Value, Inputs, Level 3 [Member] |  |  |  |
Business Combination, Contingent Consideration, Liability |  |  | 0 |
Current Maturities of Long-term Debt [Member] |  |  |  |
Capital Lease Obligations |  | 400 |  |
Long-term Debt, Net of Current Maturities [Member] |  |  |  |
Capital Lease Obligations |  |  | 500 |
Operating Income (Loss) [Member] |  |  |  |
Estimated Construction Gross (Loss) Profit, Before Tax |  | (6,300) | $ (9,700) | $ 9,100
Other Operating Income (Expense) [Member] |  |  |  |
Gain (Loss) on Sale of Long-term Contract | $ 1,400 |  |  |
Earn-out Expense |  | $ 1,200 |  |
Minimum [Member] |  |  |  |
Revenue Recognition Percentage of Completion Range |  | 12 years |  |
Warranty Term |  | 1 year |  |
Minimum [Member] | Notes Payable for Transportation and Construction Equipment [Member] |  |  |  |
Debt Instrument, Term |  | 3 years |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 3.12% |  |
Maximum [Member] |  |  |  |
Revenue Recognition Percentage of Completion Range |  | 36 years |  |
Warranty Term |  | 2 years |  |
Maximum [Member] | Notes Payable for Transportation and Construction Equipment [Member] |  |  |  |
Debt Instrument, Term |  | 5 years |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 6.92% |  |

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