Quarterly report pursuant to Section 13 or 15(d)

Contracts Receivable and Retainage (Details)

v3.8.0.1
Contracts Receivable and Retainage (Details)
$ in Thousands
3 Months Ended
Mar. 31, 2018
USD ($)
module
Dec. 31, 2017
USD ($)
Long-term Contracts or Programs Disclosure [Line Items]    
Contract receivable $ 27,359 $ 28,466
Allowance for bad debt $ 2,000  
Customer within Fabrication Division    
Long-term Contracts or Programs Disclosure [Line Items]    
Number of modules with contract receivables | module 4  
Contract Receivable | Customer Concentration Risk | Two Major Customers    
Long-term Contracts or Programs Disclosure [Line Items]    
Contract receivable $ 18,500  
Percentage of contract receivable 67.70%