Stock-based Compensation - Option Valuation Method (Detail)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Share-based Payment Arrangement, Employee
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average expected volatility	62.10%	64.67%
Weighted average risk-free interest rate	0.64%	1.18%
Weighted average expected term (in years)	5 years 1 month 24 days	5 years 11 months 19 days
Share-based Payment Arrangement, Nonemployee
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average expected volatility	69.56%	66.55%
Weighted average risk-free interest rate	0.74%	0.36%
Weighted average expected term (in years)	5 years 9 months 14 days	5 years 6 months

The risk-free interest rate assumption that is used in valuing an option on its own shares.

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- Definition

Rate of weighted-average expected volatility for award under share-based payment arrangement.

+ References

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-Publisher FASB
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-Section S99
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-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=122041274&loc=d3e301413-122809

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