Common Stock, Preferred Stock and Equity Plans - Stock and Option Plans (Details) - shares |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Awards outstanding (shares) | 10,229,110 | ||
| Additional awards authorized for grant (shares) | 15,778,703 | ||
| 2013 Stock and Option Plan | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Awards outstanding (shares) | 9,577,268 | ||
| Additional awards authorized for grant (shares) | 15,778,703 | ||
| Additional shares authorized (shares) | 5,000,000 | 8,000,000 | 6,750,000 |
| 2006 Stock and Option Plan | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Awards outstanding (shares) | 651,842 | ||
| Additional awards authorized for grant (shares) | 0 | ||
| Maximum | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Expiration period | 10 years | ||