Registered Offering and Warrants - Schedule of Estimated Fair Value of Warrant Liability (Detail) - Warrant [Member] - Level 3 [Member]	Sep. 30, 2020 USD ($) yr
Risk-Free Interest Rate [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrant and rights measurement input	0.0035
Expected Volatility [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrant and rights measurement input	1
Expected Term [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrant and rights measurement input | yr	5
Expected Dividend Yield [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrant and rights measurement input	0
Strike Price [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrant and rights measurement input	5.95
Fair Value of Common Stock [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrant and rights measurement input	4.85