Quarterly report pursuant to Section 13 or 15(d)

Contracts Receivable and Retainage (Details)

v3.7.0.1
Contracts Receivable and Retainage (Details)
$ in Thousands
 6 Months Ended
Jun. 30, 2017
USD ($)
vessel
module
Dec. 31, 2016
USD ($)
Long-term Contracts or Programs Disclosure [Line Items]    
Contract receivable $ 38,080 $ 20,169
Allowance for bad debt $ 1,300  
Two Major Customers    
Long-term Contracts or Programs Disclosure [Line Items]    
Number of vessels with contract receivables | vessel 1  
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 $ 18,000  
Percentage of contract receivable 47.40%