General form of registration statement for all companies including face-amount certificate companies

Debt and Other Financing - Schedule of Common Stock and Warrants Issued Under 2021 Bridge Financing (Detail)

v3.21.2
Debt and Other Financing - Schedule of Common Stock and Warrants Issued Under 2021 Bridge Financing (Detail) - shares
shares in Thousands
 6 Months Ended 12 Months Ended
Jun. 30, 2021
Dec. 31, 2020
Class A Common Stock [Member]    
Schedule of Common Stock and Warrants Issued Under Two Thousand and Twenty One Bridge Financing [Line Items]    
Stock Issued During Period Shares Bridge Financing 223,054 219,614
Class A Common Stock [Member] | 2021 Bridge Notes [Member]    
Schedule of Common Stock and Warrants Issued Under Two Thousand and Twenty One Bridge Financing [Line Items]    
Stock Issued During Period Shares Bridge Financing   126,572
Class A Common Stock [Member] | 2021 Bridge Notes [Member] | Incentive Shares Issued In Connection With Rights Offering [Member]    
Schedule of Common Stock and Warrants Issued Under Two Thousand and Twenty One Bridge Financing [Line Items]    
Stock Issued During Period Shares Bridge Financing 3,440  
Class A Common Stock [Member] | 2021 Bridge Notes [Member] | Debt First Tranche [Member] | 2021 Bridge Financing [Member]    
Schedule of Common Stock and Warrants Issued Under Two Thousand and Twenty One Bridge Financing [Line Items]    
Stock Issued During Period Shares Bridge Financing 126,572  
Class A Common Stock [Member] | SVB Line Of Credit [Member]    
Schedule of Common Stock and Warrants Issued Under Two Thousand and Twenty One Bridge Financing [Line Items]    
Stock Issued During Period Shares Bridge Financing   93,042
Class A Common Stock [Member] | SVB Line Of Credit [Member] | 2021 Bridge Financing [Member]    
Schedule of Common Stock and Warrants Issued Under Two Thousand and Twenty One Bridge Financing [Line Items]    
Stock Issued During Period Shares Bridge Financing 93,042  
Class A Common Stock Warrants [Member]    
Schedule of Common Stock and Warrants Issued Under Two Thousand and Twenty One Bridge Financing [Line Items]    
Class of Warrants or Rights Issued During Period 43,052  
Class A Common Stock Warrants [Member] | 2021 Bridge Notes [Member] | Incentive Shares Issued In Connection With Rights Offering [Member]    
Schedule of Common Stock and Warrants Issued Under Two Thousand and Twenty One Bridge Financing [Line Items]    
Class of Warrants or Rights Issued During Period 565  
Class A Common Stock Warrants [Member] | 2021 Bridge Notes [Member] | Debt First Tranche [Member] | 2021 Bridge Financing [Member]    
Schedule of Common Stock and Warrants Issued Under Two Thousand and Twenty One Bridge Financing [Line Items]    
Class of Warrants or Rights Issued During Period 42,487  
Class A Common Stock Warrants [Member] | SVB Line Of Credit [Member] | 2021 Bridge Financing [Member]    
Schedule of Common Stock and Warrants Issued Under Two Thousand and Twenty One Bridge Financing [Line Items]    
Class of Warrants or Rights Issued During Period 0