3. COSTS, ESTIMATED EARNINGS AND BILLINGS ON UNCOMPLETED CONTRACTS (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Billings In Excess Of Costs And Estimated Earnings On Uncompleted Contracts And Deferred Revenues
Costs incurred on uncompleted contracts	$ 9,564	$ 8,858
Estimated earnings on uncompleted contracts	10,741	6,777
Gross costs and estimated earnings	20,305	15,635
Less: Billings to date on uncompleted contracts	(19,992)	(17,907)
Costs incurred plus estimated earning less billings on uncompleted contracts, net	313	(2,272)
Included in the accompanying consolidated balance sheets under the following captions:
Costs and estimated earnings in excess of billings on uncompleted contracts	925	1,077
Billings in excess of costs and estimated earnings on uncompleted contracts	(612)	(3,349)
Total costs and estimated earnings and billings in excess of cost on uncompleted contracts	$ 313	$ (2,272)