Fair Value of Financial Assets and Liabilities - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis and Indicate Level of Fair Value Hierarchy Utilized (Detail) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Assets:
Cash equivalents	$ 155,757,000	$ 84,462,000
Available-for-sale securities	48,350,000	0
Assets Fair Value Disclosure	204,107,000	84,462,000
Level 2 [Member]
Assets:
Cash equivalents	155,757,000	84,462,000
Available-for-sale securities	48,350,000
Assets Fair Value Disclosure	$ 204,107,000	$ 84,462,000

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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-Publisher FASB
-Name Accounting Standards Codification
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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
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
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-Publisher FASB
-Name Accounting Standards Codification
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Amount of 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. Excludes cash and cash equivalents within disposal group and discontinued operation.

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-Name Accounting Standards Codification
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