Quarterly report pursuant to Section 13 or 15(d)

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

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Short-term Investments - Summary of Hierarchy for Assets Measured at Fair Value on a Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($)
$ in Thousands
Mar. 31, 2020
Dec. 31, 2019
U.S. Agency Securities [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Total Fair Value   $ 1,000
U.S. Government Securities [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Total Fair Value $ 5,003 14,993
Quoted Market Prices for Identical Assets (Level 1) [Member] | U.S. Government Securities [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Total Fair Value 5,003 14,993
Other Observable Inputs (Level 2) [Member] | U.S. Agency Securities [Member]    
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 16,337 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 $ 16,337 $ 13,219