Description of Business and Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	143,538	139,973
Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	119,257	119,257
Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	2,843	2,010
Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	613	2,440
Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	79	26
Convertible Debt
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	20,746	16,240