Fair Value Measurements - Summary Of Warrants Liability (Detail)	Sep. 30, 2020 $ / shares	Dec. 31, 2019 $ / shares
Measurement Input, Discount for Lack of Marketability [Member] \| Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input		0.28
Measurement Input, Discount for Lack of Marketability [Member] \| Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input		0.2
Fair Value Of Underlying Securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	$ 9.50
Fair Value Of Underlying Securities [Member] \| Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input		$ 8.04
Fair Value Of Underlying Securities [Member] \| Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input		$ 6.81
Expected Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.66	0.66
Risk-free Interest Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.001	0.013