Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenue, net, including related parties (Note 17)	$ 2,425	$ 1,100	$ 11,371	$ 11,934
Operating expenses:
Cost of goods sold	1,788	1,455	6,682	6,492
Research and development	1,780	1,466	5,584	8,146
Sales and marketing	663	518	2,174	2,609
General and administrative	2,733	3,092	10,328	6,606
Total operating expenses	6,964	6,531	24,768	23,853
Loss from operations	(4,539)	(5,431)	(13,397)	(11,919)
Interest expense	187	189	760	758
Loss in joint venture	1,468	1,419	6,836	3,703
Changes in fair value of promissory note	699	(2,321)	(927)	167
Other income, net	(314)	(531)	(2,157)	(1,264)
Loss before tax expense	(6,579)	(4,187)	(17,909)	(15,283)
Tax expense	0	0	0	0
Net loss	$ (6,579)	$ (4,187)	$ (17,909)	$ (15,283)
Net loss per share - basic and diluted (in usd per share)	$ (0.16)	$ (0.13)	$ (0.56)	$ (0.54)
Weighted average common shares outstanding - basic and diluted (in shares)	40,274,660	31,912,170	31,739,801	28,153,605