Net Income (Loss) per Common Share - Antidilutive securities (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Antidilutive securities
Total antidilutive securities	14,637	75,899	14,637	75,899
Stock options
Antidilutive securities
Total antidilutive securities	5,329	5,111	5,329	5,111
Restricted stock units
Antidilutive securities
Total antidilutive securities	576	914	576	914
Common Stock Warrants
Antidilutive securities
Total antidilutive securities	8,732	12,917	8,732	12,917
Convertible preferred stock
Antidilutive securities
Total antidilutive securities		2,369		2,369
Future tranche right liability
Antidilutive securities
Total antidilutive securities		54,588		54,588