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
9 Months Ended
Sep. 30, 2017
USD ($)
module
vessel
Dec. 31, 2016
USD ($)
Long-term Contracts or Programs Disclosure [Line Items]    
Contract receivable $ 25,513 $ 20,169
Number of vessels with contract receivables | vessel 1  
Allowance for bad debt $ 2,100  
Two Major Customers    
Long-term Contracts or Programs Disclosure [Line Items]    
Number of modules with contract receivables | module 4  
Two Major Customers | Contract Receivable | Customer Concentration Risk    
Long-term Contracts or Programs Disclosure [Line Items]    
Contract receivable $ 16,300  
Percentage of contract receivable 64.00%