Quarterly report pursuant to Section 13 or 15(d)

Backlog (Details Textual)

v3.7.0.1
Backlog (Details Textual) - USD ($)
$ in Millions
Jun. 30, 2017
Dec. 31, 2016
Construction [Member]    
Estimated Revenue From Uncompleted Contract $ 469.3 $ 390.2
Service [Member]    
Estimated Revenue From Uncompleted Contract $ 44.5 $ 44.1