Investments and Fair Value of Financial Instruments - Summary of Fair Value of Financial Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Assets at Fair Value
Total Assets at Fair Value	$ 11,665	$ 24,679
Treasury Bills [Member]
Assets at Fair Value
Short-term investments		1,496
Level 1 [Member]
Assets at Fair Value
Total Assets at Fair Value	11,065	8,360
Level 1 [Member] \| Treasury Bills [Member]
Assets at Fair Value
Short-term investments		1,496
Level 2 [Member]
Assets at Fair Value
Total Assets at Fair Value	600	16,319
Level 2 [Member] \| Treasury Bills [Member]
Assets at Fair Value
Short-term investments		0
Level 3 [Member]
Assets at Fair Value
Total Assets at Fair Value	0	0
Level 3 [Member] \| Treasury Bills [Member]
Assets at Fair Value
Short-term investments		0
Money Market Funds [Member]
Assets at Fair Value
Cash equivalents	11,065	6,864
Money Market Funds [Member] \| Level 1 [Member]
Assets at Fair Value
Cash equivalents	11,065	6,864
Money Market Funds [Member] \| Level 2 [Member]
Assets at Fair Value
Cash equivalents	0	0
Money Market Funds [Member] \| Level 3 [Member]
Assets at Fair Value
Cash equivalents	0	0
Commercial Paper [Member]
Assets at Fair Value
Cash equivalents		900
Short-term investments	600	12,119
Commercial Paper [Member] \| Level 1 [Member]
Assets at Fair Value
Cash equivalents		0
Short-term investments	0	0
Commercial Paper [Member] \| Level 2 [Member]
Assets at Fair Value
Cash equivalents		900
Short-term investments	600	12,119
Commercial Paper [Member] \| Level 3 [Member]
Assets at Fair Value
Cash equivalents		0
Short-term investments	$ 0	0
Corporate Securities [Member]
Assets at Fair Value
Short-term investments		3,300
Corporate Securities [Member] \| Level 1 [Member]
Assets at Fair Value
Short-term investments		0
Corporate Securities [Member] \| Level 2 [Member]
Assets at Fair Value
Short-term investments		3,300
Corporate Securities [Member] \| Level 3 [Member]
Assets at Fair Value
Short-term investments		$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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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), classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121558606&loc=SL82898722-210454

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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