Description of Business and Summary of Significant Accounting Policies - Computation of Basic and Diluted Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net income (loss)	$ 5,329	$ (9,154)	$ 31,223	$ (8,435)	$ (10,508)	$ (13,702)	$ 27,398	$ (32,645)
Accrued and undeclared preferred stock dividends in arrears	(164)			(164)			(487)	(368)
Issuance of warrants as deemed dividend - related party								(455)
Net income (loss) available to common stockholders - numerator for basic EPS	5,165			(8,599)			26,911	(33,468)
Effect of dilutive securities:
Effect of dilutive securities	191						745
Adjusted net income (loss) available to common stockholders - numerator for diluted EPS	$ 5,356			$ (8,599)			$ 27,656	$ (33,468)
Denominator:
Denominator for basic EPS - weighted average common shares outstanding	30,891,398			20,270,915			30,377,872	19,906,638
Effect of dilutive securities:
Effect of dilutive securities	2,645,440						2,980,290
Denominator for diluted EPS - adjusted weighted average common shares outstanding	33,536,838			20,270,915			33,358,162	19,906,638
Basic EPS	$ 0.17			$ (0.42)			$ 0.89	$ (1.68)
Diluted EPS	$ 0.16			$ (0.42)			$ 0.83	$ (1.68)
Redeemable Series A Preferred stock [Member]
Effect of dilutive securities:
Effect of dilutive securities	$ 9						$ 27
Effect of dilutive securities:
Effect of dilutive securities	138,597						132,647
Redeemable Series B Preferred stock [Member]
Effect of dilutive securities:
Effect of dilutive securities	$ 155						$ 460
Effect of dilutive securities:
Effect of dilutive securities	2,310,041						2,208,384
Secured Convertible Promissory Notes [Member]
Effect of dilutive securities:
Effect of dilutive securities	$ 27						$ 258
Effect of dilutive securities:
Effect of dilutive securities	196,802						639,259