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Equity and Stock-based Compensation - Summary of Common Stock Reserved for Future Issuance (Detail) - shares shares in Thousands | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Class Of Stock [Line Items] |  |
Common stock outstanding | 91,441 | 87,657
Stock options outstanding | 9,290 | 10,018
RSUs outstanding | 1,893 | 1,483
Shares reserved for future stock options and RSUs grant | 7,910 | 7,725
Total shares of common stock reserved | 114,604 | 110,220
ESPP [Member] |  |
Class Of Stock [Line Items] |  |
Shares reserved for future ESPP offering | 4,070 | 3,337

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