11. COMMON STOCK (Details Narrative) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Cash received from stock sale	$ 129,026	$ 24,368	$ 16,775
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable		6,135
June 2021 [Member]
Class of Stock [Line Items]
[custom:StockAgreementDescription]	In June 2021, we entered into a $140.0 million ATM equity offering agreement with Craig-Hallum. Under the agreement we are able, at our discretion, to offer and sell shares of our common stock having an aggregate value of up to $140.0 million through Craig-Hallum. As of December 31, 2021, we had issued
Number of shares of common stock issued	4.0
Cash received from stock sale	$ 67,800
February 2021 [Member]
Class of Stock [Line Items]
[custom:StockAgreementDescription]	In February 2021, we entered into a $50.0 million ATM equity offering agreement with Craig-Hallum. Under the agreement we were able, at our discretion, to offer and sell shares of our common stock having an aggregate value of up to $50.0 million through Craig-Hallum. We issued
Number of shares of common stock issued	2.5
Cash received from stock sale	$ 48,800
December 2020 [Member]
Class of Stock [Line Items]
[custom:StockAgreementDescription]	In December 2020, we entered into a $13.0 million ATM equity offering agreement with Craig-Hallum. Under the agreement we were able, from time to time, at our discretion to offer and sell shares of our common stock having an aggregate value of up to $13.0 million through Craig-Hallum. As of December 31, 2020, we had issued 1.0 million shares for net proceeds of $6.1 million that was received in January 2021. The $6.1 million was classified as subscriptions receivable on our December 31, 2020 balance sheet and is not included in the cash balance as of December 31, 2020. In January 2021, we issued 1.1 million shares of our common stock for net proceeds of $6.6 million under the agreement. In total, we issued
Number of shares of common stock issued	2.1
Cash received from stock sale	$ 12,700
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable		$ 6,100
November 2020 [Member]
Class of Stock [Line Items]
[custom:StockAgreementDescription]	In November 2020, we entered into a $10.0 million ATM equity offering agreement with Craig-Hallum Capital Group. Under the agreement we were able to, from time to time, at our discretion offer and sell shares of our common stock having an aggregate value of up to $10.0 million through Craig-Hallum. As of December 31, 2020, we had completed sales under such sales agreement, having sold 4.9 million shares for net proceeds of $9.6 million.
Number of shares of common stock issued		4.9
Cash received from stock sale		$ 9,600
December 2019 [Member]
Class of Stock [Line Items]
[custom:StockAgreementDescription]	In December 2019, we entered into a Common Stock Purchase Agreement with Lincoln Park granting us the right to sell shares of our common stock having an aggregate value of up to $16.0 million. Under the terms of the agreement, Lincoln Park made an initial purchase of 1.5 million shares of common stock for $1.0 million at a purchase price of $0.6531 per share. Subject to various limitations and conditions set forth in the agreement, we were able to sell up to an additional $15.0 million in shares of common stock, from time to time, at our sole discretion to Lincoln Park over a 24-month period beginning December 2019. In consideration for entering into the agreement, we issued 375,000 shares of our common stock, having a value of $277,000, based on the closing stock price at the date of grant, to Lincoln Park as a commitment fee. We incurred an additional $90,000 in issuance costs. As of December 31, 2020, we had completed sales under such sales agreement, having sold 22.2 million shares for net proceeds of $15.6 million.
Number of shares of common stock issued		22.2
Cash received from stock sale		$ 15,600