GEOGRAPHIC AND SEGMENT INFORMATION - REPORTABLE SEGMENT (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017		Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Sales	$ 11,475	$ 9,799		$ 21,391	$ 18,188
Income (loss) from operations	(267)	(1,306)		(1,131)	(3,043)
Interest expense, net	(38)	(36)		(72)	(67)
Change in fair value of derivative liabilities	46	38		20	126
Income tax expense	13	4		24	9
Depreciation and amortization	172	178		371	356
Operating Segments | Core
Segment Reporting Information [Line Items]
Sales	7,784	7,488		14,303	14,263
Income (loss) from operations	2,666	2,559	[1]	4,522	4,772	[1]
Interest expense, net	0	0		0	0
Change in fair value of derivative liabilities	0	0		0	0
Income tax expense	0	0		0	0
Depreciation and amortization	0	0		0	0
Operating Segments | Advanced Energy
Segment Reporting Information [Line Items]
Sales	3,113	1,813		5,742	2,420
Income (loss) from operations	(792)	(1,284)	[1]	(1,370)	(3,103)	[1]
Interest expense, net	0	0		0	0
Change in fair value of derivative liabilities	0	0		0	0
Income tax expense	0	0		0	0
Depreciation and amortization	0	0		0	0
Operating Segments | OEM
Segment Reporting Information [Line Items]
Sales	578	498		1,346	1,505
Income (loss) from operations	302	205	[1]	708	708	[1]
Interest expense, net	0	0		0	0
Change in fair value of derivative liabilities	0	0		0	0
Income tax expense	0	0		0	0
Depreciation and amortization	0	0		0	0
Corporate (Other)
Segment Reporting Information [Line Items]
Sales	0	0		0	0
Income (loss) from operations	(2,443)	(2,786)	[1]	(4,991)	(5,420)	[1]
Interest expense, net	(38)	(36)		(72)	(67)
Change in fair value of derivative liabilities	46	38		20	126
Income tax expense	13	4		24	9
Depreciation and amortization	$ 172	$ 178		$ 371	$ 356

[1] During the first and second quarter of 2017, marketing expenses were presented as attributable only to the Corporate (Other) segment in the line Income (loss) from operations. It was subsequently determined that certain marketing expenses are attributable to specific segments. The disclosure of Income (loss) from operations was updated for the first and second quarter of 2017 to reflect marketing expense by segment.