Fair Value Measurements - Summary Of Warrants Liability (Detail)	Sep. 29, 2020	Dec. 31, 2019
Measurement Input, Discount for Lack of Marketability [Member] \| Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input		28.0
Measurement Input, Discount for Lack of Marketability [Member] \| Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input		20.0
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	66.0	66.0
Risk-free Interest Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement Input	0.1	1.3