Fair Value Measurements - Summary of Fair Value of Financial Liabilities Assumptions (Detail)	Jan. 31, 2020 yr	Jan. 22, 2020 yr
Series A Warrant [Member] | Expected term [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and Rights Outstanding, Measurement Input		5.0
Series A Warrant [Member] | Expected volatility [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and Rights Outstanding, Measurement Input		0.43
Series A Warrant [Member] | Risk-free interest rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and Rights Outstanding, Measurement Input		0.0157
Series B Warrant [Member] | Expected term [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and Rights Outstanding, Measurement Input		2.1
Series B Warrant [Member] | Expected volatility [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and Rights Outstanding, Measurement Input		0.88
Series B Warrant [Member] | Risk-free interest rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and Rights Outstanding, Measurement Input		0.0153
warrant Issuance Obligation [Member] | Expected term [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and Rights Outstanding, Measurement Input	5.0
warrant Issuance Obligation [Member] | Expected volatility [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and Rights Outstanding, Measurement Input	0.43
warrant Issuance Obligation [Member] | Risk-free interest rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and Rights Outstanding, Measurement Input	0.0157