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Convertible Preferred Stock and Common stock - Summary of Common Stock Reserved For Issuance (Detail) - shares | Mar. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Class of Stock [Line Items] |  |
Common stock reserved for issuance | 374,015,355 | 346,016,510
Convertible preferred stock outstanding [Member] |  |
Class of Stock [Line Items] |  |
Common stock reserved for issuance | 223,033,725 | 238,954,050
Options issued and outstanding [Member] |  |
Class of Stock [Line Items] |  |
Common stock reserved for issuance | 59,603,390 | 62,827,150
Restricted stock units issued and outstanding [Member] |  |
Class of Stock [Line Items] |  |
Common stock reserved for issuance | 50,272,925 | 32,556,160
Shares available for future stock-based incentive award issuances [Member] |  |
Class of Stock [Line Items] |  |
Common stock reserved for issuance | 41,105,315 | 11,679,150

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- Definition Aggregate number of common shares reserved for future issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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