Summary of Significant Accounting Policies - Additional Information (Detail)
3 Months Ended 12 Months Ended
Dec. 31, 2020
USD ($)
Dec. 31, 2021
USD ($)
segment
Dec. 31, 2020
USD ($)
Apr. 14, 2020
USD ($)
Oct. 03, 2019
USD ($)
Property, Plant and Equipment [Line Items]          
Number of operating segments | segment   1      
Restricted cash $ 22,559,000 $ 5,056,000 $ 22,559,000    
Proceeds received from issuance of convertible unsecured promissory notes 25,000,000        
Operating lease right-of-use assets 6,856,000 5,395,000 6,856,000    
Operating lease liability 8,300,000 $ 6,756,000 $ 8,300,000    
Revenue Benchmark | Customer Concentration Risk | Three Largest Customers          
Property, Plant and Equipment [Line Items]          
Concentration risk (percent)   75.00% 92.00%    
Accounts Receivable | Customer Concentration Risk | Three Largest Customers          
Property, Plant and Equipment [Line Items]          
Concentration risk (percent)   75.00% 95.00%    
Convertible Notes Payable          
Property, Plant and Equipment [Line Items]          
Restricted cash $ 4,700,000   $ 4,700,000    
Letter of Credit          
Property, Plant and Equipment [Line Items]          
Deposit       $ 50,000 $ 750,000
Office lease | Letter of Credit          
Property, Plant and Equipment [Line Items]          
Deposit   $ 800,000      
Fleet lease | Letter of Credit          
Property, Plant and Equipment [Line Items]          
Deposit   $ 300,000      
Minimum          
Property, Plant and Equipment [Line Items]          
Useful life   3 years      
Maximum          
Property, Plant and Equipment [Line Items]          
Useful life   5 years