SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - A/R, Inventories, and Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Accounts Receivable and Allowance for Doubtful Accounts
Accounts Receivable Allowances	$ 204		$ 204		$ 209
Inventories
Raw Materials	14,397		14,397		13,870
Work in Process	307		307		3,112
Finished Goods	182		182		2,389
Reserves	(917)		(917)		(844)
Total	13,969		13,969		18,527	[1]
Impairment Analysis
Impairment charges recognized	0	$ 0	0	$ 0
Finite-Lived Intangible Assets
Gross Carrying Amount	2,233		2,233		2,230
Accumulated Amortization Amount	600		600		491
Net Book Value Amount	1,633		1,633		$ 1,739	[1]
Amortization expense	55	$ 56	109	$ 106
Estimated future annual amortization expense
Remainder of 2018	110		110
2019	219		219
2020	191		191
2021	185		185
2022	185		185
Thereafter	726		726
Total	1,616		$ 1,616
Customer Relationships
Finite-Lived Intangible Assets
Remaining lives			9 years		9 years
Gross Carrying Amount	1,302		$ 1,302		$ 1,302
Accumulated Amortization Amount	434		434		361
Net Book Value Amount	868		$ 868		$ 941
Trade Names
Finite-Lived Intangible Assets
Remaining lives			3 years		20 years
Gross Carrying Amount	100		$ 100		$ 814
Accumulated Amortization Amount	44		44		102
Net Book Value Amount	56		$ 56		$ 712
Intellectual Property
Finite-Lived Intangible Assets
Remaining lives			20 years		3 years
Gross Carrying Amount	814		$ 814		$ 100
Accumulated Amortization Amount	122		122		28
Net Book Value Amount	692		$ 692		$ 72
Patents
Finite-Lived Intangible Assets
Remaining lives			7 years		7 years
Gross Carrying Amount	17		$ 17		$ 14
Net Book Value Amount	$ 17		$ 17		$ 14

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