v3.22.2.2
Stockholders' Equity - Summary of Option Activity (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 9 Months Ended 12 Months Ended
Sep. 30, 2022
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
2008 Stock Plan [Member]        
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]        
Beginning Balance, Shares Available for Grant 375,546 2,009,978 1,927,978  
Options granted, Shares Available for Grant   (3,609,610) (1,393,713)  
Options exercised, Shares Available for Grant   0 0  
Options expired, Shares Available for Grant   1,975,178 1,475,713  
Ending Balance, Shares Available for Grant   375,546 2,009,978 1,927,978
Beginning Balance, Outstanding Stock Options 10,056,990 8,473,849 8,558,849  
Options granted, Outstanding Stock Options   3,609,610 1,393,713  
Options exercised, Outstanding Stock Options   (51,291) (3,000)  
Options expired, Outstanding Stock Options   (1,975,178) (1,475,713)  
Ending Balance, Outstanding Stock Options   10,056,990 8,473,849 8,558,849
Options vested and exercisable, Outstanding Stock Options   9,327,678    
Options vested and expected to vest, Outstanding Stock Options   10,056,990    
Beginning Balance, Weighted- Average Exercise Price Per Share $ 1.49 $ 0.75 $ 0.48  
Options granted, Weighted- Average Exercise Price Per Share   2.43 1.73  
Options exercised, Weighted- Average Exercise Price Per Share   0.28 0.03  
Options expired, Weighted- Average Exercise Price Per Share   0.28 0.1  
Ending balance, Weighted- Average Exercise Price Per Share   1.49 $ 0.75 $ 0.48
Options vested and exercisable, Weighted- Average Exercise Price Per Share   1.46    
Options vested and expected to vest, Weighted- Average Exercise Price Per Share   $ 1.49    
Weighted- Average Remaining Contractual Life (Years)   6 years 6 months 10 days 4 years 6 months 7 days 3 years 9 months 25 days
Options vested and exercisable, Weighted- Average Remaining Contractual Life (Years)   6 years 4 months 6 days    
Options vested and expected to vest, Weighted- Average Remaining Contractual Life (Years)   6 years 6 months 10 days    
Beginning Balance, Average Intrinsic Value $ 10,995 $ 14,068 $ 11,137  
Options exercised, Average Intrinsic Value   28 1  
Ending Balance, Average Intrinsic Value   10,995 $ 14,068 $ 11,137
Options vested and exercisable, Average Intrinsic Value   10,401    
Options vested and expected to vest, Average Intrinsic Value   $ 10,995    
2016 Equity Incentive Plan [Member]        
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]        
Beginning Balance, Shares Available for Grant 5,749,559 1,321,017 1,124,473  
Options granted, Shares Available for Authorized   9,099,380    
Options granted, Shares Available for Grant   (4,707,235) 0  
Options exercised, Shares Available for Grant   0 0  
Options expired, Shares Available for Grant   36,397 196,544  
Ending Balance, Shares Available for Grant   5,749,559 1,321,017 1,124,473
Beginning Balance, Outstanding Stock Options 10,372,865 5,731,145 6,000,484  
Options granted, Outstanding Stock Options 3,875,000 4,707,235 0  
Options exercised, Outstanding Stock Options   (29,118) (72,795)  
Options expired, Outstanding Stock Options   (36,397) (196,544)  
Ending Balance, Outstanding Stock Options 14,216,000 10,372,865 5,731,145 6,000,484
Options vested and exercisable, Outstanding Stock Options   6,348,921    
Options vested and expected to vest, Outstanding Stock Options   10,372,865    
Beginning Balance, Weighted- Average Exercise Price Per Share $ 0.85 $ 0.09 $ 0.1  
Options granted, Weighted- Average Exercise Price Per Share $ 2.62 1.77 0  
Options exercised, Weighted- Average Exercise Price Per Share   0.05 0.05  
Options expired, Weighted- Average Exercise Price Per Share   0.21 0.35  
Ending balance, Weighted- Average Exercise Price Per Share   0.85 $ 0.09 $ 0.1
Options vested and exercisable, Weighted- Average Exercise Price Per Share   0.28    
Options vested and expected to vest, Weighted- Average Exercise Price Per Share   $ 0.85    
Weighted- Average Remaining Contractual Life (Years)   5 years 10 months 9 days 4 years 10 months 24 days  
Options vested and exercisable, Weighted- Average Remaining Contractual Life (Years)   3 years 6 months 21 days    
Options vested and expected to vest, Weighted- Average Remaining Contractual Life (Years)   5 years 10 months 9 days 3 years 9 months 14 days  
Beginning Balance, Average Intrinsic Value $ 16,208 $ 9,654 $ 2,104  
Options exercised, Average Intrinsic Value   54 29  
Ending Balance, Average Intrinsic Value   16,208 $ 9,654 $ 2,104
Options vested and exercisable, Average Intrinsic Value   13,542    
Options vested and expected to vest, Average Intrinsic Value   $ 16,208