Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating Activities
Net loss	$ (9,253)	$ (6,136)
Adjustments to reconcile net loss to net cash used in operating activities:
(Gain) from change in fair value of derivative warrant liability	(7)	(1)
(Gain) from change in fair value of 2020/21 Notes and 2020 Notes embedded derivative liability	100	(246)
Stock-based compensation	172	263
Depreciation and amortization	1,649	1,612
Non-cash lease expense	15	12
Non-cash interest expense	150	410
Changes in operating assets and liabilities:
Accounts receivable	983	(599)
Inventories	520	(21)
Prepaid expenses and other current assets, deposits and other assets	(167)	157
Accounts payable, accrued expenses, and long-term liabilities	(1,150)	(1,159)
Net cash used in operating activities	(6,988)	(5,708)
Investing Activities
Acquisitions of property, plant and equipment	(777)	(2,204)
Net cash used in investing activities	(777)	(2,204)
Financing Activities
Debt and equity offering costs	(52)	(234)
Proceeds from issuance of common stock, net	958	9,878
Payment of loans payable - other	(154)
Net cash provided by financing activities	752	9,644
Net (decrease) increase in cash and cash equivalents	(7,013)	1,732
us-gaap_CashAndCashEquivalentsAbstract
Beginning of period	16,302	33,734
End of period	9,289	35,466
Cash paid for interest	395	345
Non-cash purchase of property, plant and equipment	380	1,316
Original issue discount paid with 2020/21 Notes	282
Right-of-use asset purchased with financing lease	13
Fair value of right-to-use asset and related lease liability upon adoption of ASC 842 - Leases		$ 1,244