Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation - Weighted-Average Fair Value Valuation Assumptions (Detail)

v3.20.1
Stock Based Compensation - Weighted-Average Fair Value Valuation Assumptions (Detail) - Employee Stock Options - $ / shares
3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Risk-free interest rate 1.83% 2.59%
Expected term (in years) 6 years 29 days 6 years 29 days
Dividend yield 0.00% 0.00%
Volatility 110.00% 109.00%
Weighted-average fair value of stock options granted $ 12.13 $ 3.93