4. BILLINGS, COSTS AND ESTIMATED EARNINGS ON UNCOMPLETED CONTRACTS (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Billings In Excess Of Costs And Estimated Earnings On Uncompleted Contracts And Deferred Revenues
Costs incurred on uncompleted contracts	$ 8,962	$ 9,915
Estimated earnings on uncompleted contracts	4,597	4,714
Gross costs and estimated earnings	13,559	14,629
Less: Billings to date on uncompleted contracts	(11,350)	(12,835)
Total	2,209	1,794
Included in the accompanying condensed consolidated balance sheets under the following captions:
Costs and estimated earnings in excess of billings on uncompleted contracts	3,432	2,547
Billings in excess of costs and estimated earnings on uncompleted contracts	(1,223)	(753)
Total	$ 2,209	$ 1,794