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
 3 Months Ended
Mar. 31, 2017
USD ($)
vessel
module
Dec. 31, 2016
USD ($)
Long-term Contracts or Programs Disclosure [Line Items]    
Contract receivable $ 21,061 $ 20,169
Allowance for bad debt $ 1,200  
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 $ 9,400  
Percentage of contract receivable 44.60%