Fair Value Measurements - Schedule of Assumptions Used to Estimate Fair Values of Common Stock Warrants (Detail) - Series A warrants	Mar. 31, 2020	Dec. 31, 2019
Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assumptions used to estimate fair value of common stock warrants	0.003	0.016
Expected dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assumptions used to estimate fair value of common stock warrants	0.000	0.000
Expected volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assumptions used to estimate fair value of common stock warrants	0.749	0.772
Expected Term
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected term (in years)	2 years 6 months	2 years 9 months 18 days