Fair Value Measurements and Marketable Securities - Summary of Gross Unrealized Gains and Losses of Marketable Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 24,497	$ 52,299
Gross Unrealized Gains		18
Gross Unrealized Losses	(19)	(2)
Fair Value	24,478	52,315
U.S. Government Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		16,791
Gross Unrealized Gains		6
Fair Value		16,797
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	13,532	14,050
Gross Unrealized Gains		12
Gross Unrealized Losses	(19)	(2)
Fair Value	13,513	14,060
Commercial Paper [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	10,965	21,458
Fair Value	$ 10,965	$ 21,458

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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