Description of Business and Significant Accounting Policies - Schedule of Antidilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock equivalents excluded from the computation of diluted net loss per common share	113,045,000	106,550,000
Series B Convertible Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock equivalents excluded from the computation of diluted net loss per common share	425,000	425,000
Series C Redeemable Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock equivalents excluded from the computation of diluted net loss per common share	42,130,000	42,130,000
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock equivalents excluded from the computation of diluted net loss per common share	20,400,000	23,655,000
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock equivalents excluded from the computation of diluted net loss per common share	50,090,000	40,340,000