Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Summary of Hierarchy for Assets Measured at Fair Value on a Recurring Basis (Detail)

v3.20.2
Fair Value Measurements - Summary of Hierarchy for Assets Measured at Fair Value on a Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($)
$ in Thousands
Jun. 30, 2020
Dec. 31, 2019
US Government Agencies Debt Securities    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Total Fair Value   $ 1,000
US Government Debt Securities    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Total Fair Value   14,993
Quoted Market Prices for Identical Assets (Level 1) [Member] | US Government Debt Securities    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Total Fair Value   14,993
Other Observable Inputs (Level 2) [Member] | US Government Agencies Debt Securities    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Total Fair Value   1,000
Money market Funds [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Total Fair Value $ 18,389 13,219
Money market Funds [Member] | Quoted Market Prices for Identical Assets (Level 1) [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Total Fair Value $ 18,389 $ 13,219