GEOGRAPHIC AND SEGMENT INFORMATION - Geographic (Details) - USD ($) $ in Thousands	3 Months Ended								6 Months Ended	9 Months Ended		12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Sales	$ 8,382	$ 7,575	$ 6,649	$ 5,629	$ 5,845	$ 3,672	$ 3,691	$ 3,397	$ 12,278	$ 19,853	$ 10,760	$ 28,235	$ 16,605	$ 10,234
Domestic
Segment Reporting Information [Line Items]
Sales												19,584	12,858	8,887
International
Segment Reporting Information [Line Items]
Sales												$ 8,651	$ 3,747	$ 1,347