Net (Loss) Income per Share Attributable to Common Stockholders - Antidilutive Securities (Details) - shares shares in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2018 |
Jul. 01, 2017 |
Jun. 30, 2018 |
Jul. 01, 2017 |
|
| Stock options | ||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
| Antidilutive securities (shares) | 4,002 | 1,398 | 971 | 1,292 |
| Restricted stock units | ||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
| Antidilutive securities (shares) | 2,514 | 24 | 685 | 14 |
| 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) | 4,915 | 5 | 4,915 | 5 |