Stockholders' Equity - Outstanding and Reserved Shares of Common Stock for Future Issuance (Detail) - shares |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|---|
| Class of Stock [Line Items] | |||
| Options outstanding (in shares) | 1,154,000 | 1,811,000 | 3,370,000 |
| Total reserved shares of common stock for future issuance (in shares) | 49,724,000 | ||
| 2012 Equity Incentive Plan | |||
| Class of Stock [Line Items] | |||
| Total reserved shares of common stock for future issuance (in shares) | 29,641,000 | ||
| 2012 Employee Stock Purchase Plan | |||
| Class of Stock [Line Items] | |||
| Total reserved shares of common stock for future issuance (in shares) | 10,196,000 | ||
| Common stock options | |||
| Class of Stock [Line Items] | |||
| Options outstanding (in shares) | 1,154,000 | ||
| Restricted stock units | |||
| Class of Stock [Line Items] | |||
| RSUs (in shares) | 8,733,000 | 10,202,000 | 11,403,000 |