DEBT AND CREDIT AGREEMENTS (Details) - USD ($) $ in Thousands	Oct. 26, 2016	Jun. 30, 2018	Dec. 31, 2017	Mar. 31, 2017
Credit Facilities
Line of credit		$ 14,516
Short-term Non-bank Loans and Notes Payable		2,600
Less: Current portion		(18,024)	$ (14,252)
Long-term debt, net of current maturities		1,995	797
Current borrowing capacity		9,634
Current maturities of long-term debt			114
New Markets Tax Credit Transaction
Credit Facilities
Short-term Non-bank Loans and Notes Payable		2,600
Capital Expenditure loan
Credit Facilities
Long-term debt		2,333	1,146
Current maturities of long-term debt		907	804
Development Corporation of Abilene loan
Credit Facilities
Long-term debt		570	570
Credit facility
Credit Facilities
Maximum borrowing capacity	$ 20,000			$ 25,000
Line of credit facilities, term of credit agreements	3 years
Maximum borrowing capacity of the face value of eligible A/R (as a percent)	85.00%
Maximum percentage of book value of inventories that may be financed	50.00%
Maximum borrowing capacity of the face value of machinery, equipment and property that may be financed	50.00%
Annual unused line fee (as a percent)	0.50%
Credit facility | Minimum
Credit Facilities
Variable rate basis	2.25%
Interest rate margin (as a percent)	0.00%
Credit facility | Maximum
Credit Facilities
Maximum borrowing capacity	$ 10,000
Variable rate basis	3.00%
Interest rate margin (as a percent)	1.00%
Line of credit
Credit Facilities
Line of credit		14,516	10,733
Term loans and notes payable | New Markets Tax Credit Transaction
Credit Facilities
Short-term Non-bank Loans and Notes Payable		$ 2,600	$ 2,600