Consolidated Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	Prior Year Adjustment of Warrants	Common Stock	Additional Paid in Capital	Additional Paid in Capital Prior Year Adjustment of Warrants	Accumulated Other Comprehensive Loss	Accumulated Deficit	Accumulated Deficit Prior Year Adjustment of Warrants
Balance (in shares) at Dec. 31, 2020			175,912,194
Balance at Dec. 31, 2020	$ 340,823	$ 0	$ 18	$ 656,717	$ (1,585)	$ (230)	$ (315,682)	$ 1,585
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under warrant exercises (in shares)			6,973,882
Issuance of common stock under warrant exercises	80,200		$ 1	80,199
Issuance of common stock under employee stock award plans, net of taxes (in shares)			6,798,504
Issuance of common stock under employee stock award plans, net of taxes	(37)			(37)
Share-based compensation	11,530			11,530
Other comprehensive income (loss), net of tax	(22)					(22)
Net loss	(40,817)						(40,817)
Balance (in shares) at Mar. 31, 2021			189,684,580
Balance at Mar. 31, 2021	391,677		$ 19	746,824		(252)	(354,914)
Balance (in shares) at Dec. 31, 2021			197,346,675
Balance at Dec. 31, 2021	299,263		$ 20	825,988		(412)	(526,333)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under warrant exercises	5,303			5,303
Issuance of common stock under employee stock award plans, net of taxes (in shares)			916,819
Share-based compensation	4,938			4,938
Other comprehensive income (loss), net of tax	(729)					(729)
Net loss	(49,121)						(49,121)
Balance (in shares) at Mar. 31, 2022			198,263,494
Balance at Mar. 31, 2022	$ 259,654		$ 20	$ 836,229	$ (1,600)	$ (1,141)	$ (575,454)	$ 1,600