COSTS AND ESTIMATED PROFITS ON UNCOMPLETED CONTRACTS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Schedule of costs and estimated earnings on uncompleted contracts [Abstract]
Costs incurred on uncompleted contracts	$ 69,861	$ 53,595
Estimated profits, thereon	8,744	6,847
Total	78,605	60,442
Less: billings to date	48,662	38,662
Net	29,943	21,780
Schedule of Costs and Estimated Earnings on Uncompleted Contracts Included in Condensed Consolidated Balance Sheets [Abstract]
Costs and estimated profits in excess of billings	38,150	32,514
Billings in excess of costs and estimated profits	(8,207)	(10,696)
Translation adjustment	0	(38)
Net	29,943	$ 21,780
Balances previously classified as contract liabilities at the beginning of the period that have shipped	$ 8,300