Marketable Securities - Summary of Marketable Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 5,033	$ 62,306
Gross Unrealized Gains	4	45
Fair Value	5,037	62,351
U.S. treasury securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	5,033	5,020
Gross Unrealized Gains	4	12
Fair Value	$ 5,037	5,032
Corporate debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		28,204
Gross Unrealized Gains		20
Fair Value		28,224
Asset-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		17,108
Gross Unrealized Gains		13
Fair Value		17,121
Commercial paper [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		11,974
Fair Value		$ 11,974

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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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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Amount 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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