Summary of Cash, Cash Equivalents and Marketable Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	$ 33,620	$ 47,745
Fair Value	33,620	47,745
Amortized Cost	23,457	29,785
Fair Value	23,457	29,785
Amortized Cost	10,163	17,960
Fair Value	10,163	17,960
Cash and money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	23,457	25,278
Fair Value	23,457	25,278
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost		4,507
Fair Value		4,507
Amortized Cost	10,163	17,960
Fair Value	$ 10,163	$ 17,960