Summary of Certain Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Schedule Of Accounting Policies [Line Items]
Non-time and material jobs of short term nature duration description	less than one month
Refinancing of outstanding loans used as working capital		$ 1.0
Continuing Operations
Schedule Of Accounting Policies [Line Items]
Cost and estimated earnings in excess of billings on uncompleted contracts	$ 1.2	0.6
Continuing Operations | Brazil
Schedule Of Accounting Policies [Line Items]
Order backlog	1.0	$ 2.2
Discontinued Operations | Held-for-sale
Schedule Of Accounting Policies [Line Items]
Cost and estimated earnings in excess of billings on uncompleted contracts	$ 0.0		$ 5.8