Quarterly report pursuant to Section 13 or 15(d)

Revenue Recognition on Construction Contract and Other Service Revenues (Details)

v3.8.0.1
Revenue Recognition on Construction Contract and Other Service Revenues (Details) - Construction Contract Revenue
$ in Thousands
3 Months Ended
Mar. 31, 2018
USD ($)
compensation_arrangement
Mar. 31, 2017
USD ($)
Disaggregation of Revenue [Line Items]    
Number of compensation arrangement types | compensation_arrangement 3  
Performance obligations satisfied or already satisfied $ 309 $ 146
Customers payment period 30 days  
Remaining performance obligations $ 23,500