Consolidated Statements of Changes in Stockholders' Equity (Deficit) - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-In Capital	AOCI Attributable to Parent [Member]	Accumulated Deficit	Series A Preferred Stock	Total
Balance at Dec. 31, 2018	$ 177	$ 428,878		$ (357,794)		$ 71,261
Balance (in shares) at Dec. 31, 2018	176,918
Changes in Stockholders' Equity (Deficit)
Issuance of common stock, net	$ 26	26,731				26,757
Issuance of common stock (in shares)	26,136
Exercise of stock options and warrants		108				108
Exercise of stock options and warrants (in shares)	256
Exchange and conversion of convertible notes, net		8,052				8,052
Exchange and conversion of convertible notes, net (in shares)	143
Stock-based compensation expense and vesting of RSUs		722				722
Net loss				(115,549)		(115,549)
Balance at Dec. 31, 2019	$ 203	464,491		(473,343)		(8,649)
Balance (in shares) at Dec. 31, 2019	203,453
Changes in Stockholders' Equity (Deficit)
Issuance of common stock, net		(26)				(26)
Issuance of common stock (in shares)	329
Exercise of stock options and warrants	$ 3	573				576
Exercise of stock options and warrants (in shares)	3,329
Exchange and conversion of convertible notes, net	$ 60	27,199				27,259
Exchange and conversion of convertible notes, net (in shares)	58,470
Stock-based compensation expense and vesting of RSUs		7,314				7,314
Issuance of warrants related to debt, net		4,611				4,611
Net loss				(175,168)		(175,168)
Balance at Dec. 31, 2020	$ 266	504,162		(648,511)		(144,083)
Balance (in shares) at Dec. 31, 2020	265,581
Increase (Decrease) in Temporary Equity
Issuance of convertible preferred stock, net					$ 2,811
Temporary Equity, Ending Balance at Dec. 31, 2020					2,811
Changes in Stockholders' Equity (Deficit)
Conversion of preferred stock	$ 54	45,511				45,565
Conversion of preferred stock (in shares)	54,166
Issuance of common stock, net	$ 113	200,252				200,365
Issuance of common stock (in shares)	112,571
Exercise of stock options and warrants	$ 5	4,988				4,993
Exercise of stock options and warrants (in shares)	5,732
Exchange and conversion of convertible notes, net	$ 5	6,496				6,501
Exchange and conversion of convertible notes, net (in shares)	4,925
Issuance of common stock for vested RSUs and ESPP purchase	$ 6	68				74
Issuance of common stock for vested RSUs and ESPP purchase (in shares)	5,816
Shares withheld related to net share settlement	$ (2)	(5,291)				(5,293)
Shares withheld related to net share settlement (in shares)	(1,509)
Stock-based compensation expense		9,029				9,029
Net loss				(302,474)		(302,474)
Other comprehensive income, net of tax			$ (212)			(212)
Balance at Dec. 31, 2021	$ 447	$ 765,215	$ (212)	$ (950,985)		$ (185,535)
Balance (in shares) at Dec. 31, 2021	447,282
Increase (Decrease) in Temporary Equity
Issuance of convertible preferred stock, net					42,756
Conversion of preferred stock					$ (45,567)