SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - A/R, Inventories, and Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Accounts Receivable and Allowance for Doubtful Accounts
Accounts Receivable Allowances	$ 209		$ 209
Inventories
Raw Materials	13,489		13,870
Work in Process	401		3,112
Finished Goods	174		2,389
Reserves	(1,027)		(844)
Total	13,037		18,527	[1]
Impairment Analysis
Impairment charges recognized	0
Finite-Lived Intangible Assets
Gross Carrying Amount	2,233		2,230
Accumulated Amortization Amount	546		491
Net Book Value Amount	1,687		$ 1,739	[1]
Amortization expense	55	$ 50
Estimated future annual amortization expense
Remainder of 2018	164
2019	219
2020	191
2021	185
2022	185
Thereafter	726
Total	$ 1,670
Customer Relationships
Finite-Lived Intangible Assets
Remaining lives	9 years		9 years
Gross Carrying Amount	$ 1,302		$ 1,302
Accumulated Amortization Amount	398		361
Net Book Value Amount	$ 904		$ 941
Trade Names
Finite-Lived Intangible Assets
Remaining lives	3 years		20 years
Gross Carrying Amount	$ 100		$ 814
Accumulated Amortization Amount	36		102
Net Book Value Amount	$ 64		$ 712
Intellectual Property
Finite-Lived Intangible Assets
Remaining lives	20 years		3 years
Gross Carrying Amount	$ 814		$ 100
Accumulated Amortization Amount	112		28
Net Book Value Amount	$ 702		$ 72
Patents
Finite-Lived Intangible Assets
Remaining lives	7 years		7 years
Gross Carrying Amount	$ 17		$ 14
Net Book Value Amount	$ 17		$ 14

[1] The balance sheet at December 31, 2017 has been derived from the audited financial statements at that date