Stockholders' Equity - Stock Options - Additional Information (Detail) - USD ($)	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expenses	$ 14,800,000
Unrecognized compensation expense, weighted-average period	1 year 10 months 17 days
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expenses	$ 74,000
Unrecognized compensation expense, weighted-average period	1 month 13 days
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	$ 8,100,000	$ 4,600,000
Unrecognized compensation expenses	$ 55,200,000
Unrecognized compensation expense, weighted-average period	2 years 6 months

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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Amount of cost to be recognized for option under share-based payment arrangement.

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