Short-term Investments - Summary of Debt Securities by Major Security Type (Detail) $ in Thousands	Dec. 31, 2019 USD ($)
Debt Securities, Available-for-sale [Line Items]
Amortized cost	$ 15,967
Gross unrealized gains	26
Fair value	15,993
U.S. Agency Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized cost	1,000
Fair value	1,000
U.S. Government Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized cost	14,967
Gross unrealized gains	26
Fair value	$ 14,993

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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-Section 50
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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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 210
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-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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