2. Liquidity (Details Narrative) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	May 24, 2021	Jan. 28, 2021
Affiliate, Collateralized Security [Line Items]
Cash received from stock sale	$ 64,476	$ 97,957	$ 8,850
Financing available under Form S-3 shelf registration statement	$ 95,100	$ 95,100
May 242021 [Member]
Affiliate, Collateralized Security [Line Items]
Number of shares of common stock issued		22,258,066
Shares Issued, Price Per Share				$ 3.10
Cash received from stock sale		$ 64,500
Offering proceeds used to partially repay certain convertible promissory notes		$ 7,300
January 282021 [Member]
Affiliate, Collateralized Security [Line Items]
Number of shares of common stock issued		17,530,488
Shares Issued, Price Per Share					$ 2.05
Cash received from stock sale		$ 33,500
Offering proceeds used to partially repay certain convertible promissory notes		$ 3,800