Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended		39 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Mar. 31, 2018
Income Statement [Abstract]
NET REVENUE	$ 30,368	$ 14,588	$ 48,213	$ 28,904			$ 6,200
COST OF GOODS SOLD	18,608	10,808	29,783	21,658
GROSS PROFIT	11,760	3,780	18,430	7,246
OPERATING EXPENSES:
Sales and distribution	13,709	8,163	22,982	16,956
Research and development	3,342	897	4,505	2,019
General and administrative	10,305	3,130	13,671	5,336
TOTAL OPERATING EXPENSES:	27,356	12,190	41,158	24,311
OPERATING LOSS	(15,596)	(8,410)	(22,728)	(17,065)	$ 29,400	$ 22,600
INTEREST EXPENSE—net	1,281	506	2,494	1,063
OTHER EXPENSE (INCOME)—net	(13)	16	31	(25)
LOSS BEFORE INCOME TAXES	(16,864)	(8,932)	(25,253)	(18,103)
PROVISION FOR INCOME TAXES	15	3	15	3
NET LOSS	$ (16,879)	$ (8,935)	$ (25,268)	$ (18,106)
Net loss per share, basic and diluted	$ (1.38)	$ (0.90)	$ (2.13)	$ (1.95)
Weighted-average number of shares outstanding, basic and diluted	12,206,747	9,963,851	11,872,326	9,273,735