Condensed Consolidated Statements of Stockholders' Deficit (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Treasury Stock
Beginning Balance at Dec. 31, 2020	$ (106,994)	$ 59	$ 452,992	$ (541,274)	$ (18,771)
Beginning Balance, shares at Dec. 31, 2020		59,287,331			(3,515,028)
Issuance of stock, net	11,262	$ 4	11,258
Issuance of stock, net, shares		4,370,629
Exercise of common stock options	88		88
Exercise of common stock options, shares		71,284
Issuance of common stock upon vesting of restricted stock units	(229)		(228)		$ (1)
Issuance of common stock upon vesting of restricted stock units, shares		174,730			(48,581)
Stock-based compensation expense	2,630		2,630
Net loss	(32,264)			(32,264)
Ending Balance at Mar. 31, 2021	(125,507)	$ 63	466,740	(573,538)	$ (18,772)
Ending Balance, shares at Mar. 31, 2021		63,903,974			(3,563,609)
Beginning Balance at Dec. 31, 2020	(106,994)	$ 59	452,992	(541,274)	$ (18,771)
Beginning Balance, shares at Dec. 31, 2020		59,287,331			(3,515,028)
Net loss	(110,795)
Ending Balance at Jun. 30, 2021	(139,609)	$ 82	531,156	(652,069)	$ (18,778)
Ending Balance, shares at Jun. 30, 2021		81,995,756			(3,648,101)
Beginning Balance at Mar. 31, 2021	(125,507)	$ 63	466,740	(573,538)	$ (18,772)
Beginning Balance, shares at Mar. 31, 2021		63,903,974			(3,563,609)
Issuance of stock, net	12,007	$ 16	11,991
Issuance of stock, net, shares		15,694,332
Exercise of common stock options	20		26		$ (6)
Exercise of common stock options, shares		25,498			(5,050)
Issuance of common stock under employee stock purchase plan	561	$ 1	560
Issuance of common stock under employee stock purchase plan, shares		254,832
Issuance of common stock upon vesting of restricted stock units	(251)		(251)
Issuance of common stock upon vesting of restricted stock units, shares		237,388			(79,442)
Issuance of stock purchase warrant	41,926		41,926
Issuance of common stock upon conversion of debt, net	2,069	$ 1	2,068
Issuance of common stock upon conversion of debt, net, shares		611,616
Issuance of common stock upon conversion of interest, net	3,627	$ 1	3,626
Issuance of common stock upon conversion of interest, net, shares		1,268,116
Stock-based compensation expense	4,470		4,470
Net loss	(78,531)			(78,531)
Ending Balance at Jun. 30, 2021	(139,609)	$ 82	531,156	(652,069)	$ (18,778)
Ending Balance, shares at Jun. 30, 2021		81,995,756			(3,648,101)
Beginning Balance at Dec. 31, 2021	(84,976)	$ 146	722,646	(788,686)	$ (19,082)
Beginning Balance, shares at Dec. 31, 2021		185,736,890			(3,864,214)
Issuance of stock, net	3,626	$ 2	3,624
Issuance of stock, net, shares		2,130,327
Issuance of common stock upon vesting of restricted stock units	(80)		(80)
Issuance of common stock upon vesting of restricted stock units, shares		288,003			(93,076)
Stock-based compensation expense	2,053		2,053
Net loss	(13,808)			(13,808)
Ending Balance at Mar. 31, 2022	(93,185)	$ 148	728,243	(802,494)	$ (19,082)
Ending Balance, shares at Mar. 31, 2022		188,155,220			(3,957,290)
Beginning Balance at Dec. 31, 2021	$ (84,976)	$ 146	722,646	(788,686)	$ (19,082)
Beginning Balance, shares at Dec. 31, 2021		185,736,890			(3,864,214)
Exercise of common stock options, shares	0
Net loss	$ (19,321)
Ending Balance at Jun. 30, 2022	(96,106)	$ 150	730,833	(808,007)	$ (19,082)
Ending Balance, shares at Jun. 30, 2022		190,322,688			(4,032,710)
Beginning Balance at Mar. 31, 2022	(93,185)	$ 148	728,243	(802,494)	$ (19,082)
Beginning Balance, shares at Mar. 31, 2022		188,155,220			(3,957,290)
Issuance of stock, net	1,168	$ 2	1,166
Issuance of stock, net, shares		1,725,723
Issuance of common stock under employee stock purchase plan	89		89
Issuance of common stock under employee stock purchase plan, shares		125,059
Issuance of common stock upon vesting of restricted stock units	(111)		(111)
Issuance of common stock upon vesting of restricted stock units, shares		316,686			(75,420)
Stock-based compensation expense	1,446		1,446
Net loss	(5,513)			(5,513)
Ending Balance at Jun. 30, 2022	$ (96,106)	$ 150	$ 730,833	$ (808,007)	$ (19,082)
Ending Balance, shares at Jun. 30, 2022		190,322,688			(4,032,710)