Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Additional Information (Detail)

v3.21.2
Stockholders' Equity - Additional Information (Detail) - USD ($)
1 Months Ended 6 Months Ended
Feb. 29, 2020
Jul. 31, 2019
Jun. 30, 2021
Dec. 31, 2020
Jun. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Authorized capital stock     520,000,000    
Common stock, par value     $ 0.0001 $ 0.0001  
Common stock, shares authorized     500,000,000 500,000,000  
Preferred stock, par value     $ 0.0001    
Preferred stock, shares authorized     20,000,000    
Preferred stock, shares outstanding     0 0  
Stock option granted description terms     the exercise price of an option granted to a 10% shareholder cannot be less than 110% of the estimated fair value of the shares on the date of grant. Options granted generally vest over four years and expire in seven to ten years.    
Ownership percent     10.00%    
Shares of common stock, reserved for issuance     20,293,665    
2014 Equity Incentive Plan          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Shares of common stock, reserved for issuance     16,773,438    
Outstanding options and RSUs     13,213,894    
Aggregate number of awards available for grant to be issued     3,559,544    
Inducement Plan          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Shares of common stock, reserved for issuance     2,547,962    
Outstanding options and RSUs     2,032,323    
Aggregate number of awards available for grant to be issued     515,639    
Additional shares of common stock, reserved for issuance     1,500,000    
Restricted Stock Units (RSUs)          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Unrecognized stock-based compensation expense     $ 76,700,000    
Unrecognized stock-based compensation weighted average recognition period     2 years 9 months 18 days    
Restricted Stock Units (RSUs) | From Date Of Grant          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Share based compensation, vesting period     4 years    
Employees And Non Employees          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Share based compensation, vesting period     4 years    
Vested and Unvested Options          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Unrecognized stock-based compensation weighted average recognition period     2 years 9 months 18 days    
Unrecognized stock-based compensation     $ 55,200,000    
Maximum | Employees And Non Employees          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Share based compensation award expiration period     10 years    
Minimum          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Percentage of employees purchase price of common stock     100.00%    
Minimum | 10% Shareholder          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Percentage of employees purchase price of common stock     110.00%    
Minimum | Employees And Non Employees          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Share based compensation award expiration period     7 years    
Underwritten Public Offering | 2019 Warrants          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Warrants outstanding     2,888,526    
Underwritten Public Offering | Warrant          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Number of warrants issued   2,945,026   2,040,816 2,866,961
Number of securities called by each warrant   1      
Warrants, exercise price   $ 0.0001      
Warrants, term   7 years      
Maximum ownership Percentage   9.99%      
Underwritten Public Offering | Warrant | Maximum          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Maximum ownership Percentage   19.99%      
Underwritten Public Offering | Warrant | Minimum          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Prior notice period   61 days      
At The Market Offering | Maximum | Cowen          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Common stock aggregate offering price $ 100,000,000.0        
Percentage of commission to be paid on gross sales proceeds of common stock sold 3.00%        
2020 ATM Facility | Cowen          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Common stock, shares issued     145,630    
Common stock average price     $ 17.31    
Proceeds from sale of common stock, gross     $ 2,500,000    
Proceeds from sale of common stock, net     2,400,000    
Common stock value remaining to be sold     $ 77,100,000