Net (Loss) Income per Share Attributable to Common Stockholders - Antidilutive Securities (Details) - shares shares in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2018 |
Apr. 01, 2017 |
|
| Stock options | ||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
| Antidilutive securities (shares) | 954 | 2,962 |
| Restricted stock units | ||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
| Antidilutive securities (shares) | 294 | 1,391 |
| Series A Redeemable Convertible Preferred Stock (as converted to common stock) | ||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
| Antidilutive securities (shares) | 4,851 | 5 |