v3.8.0.1
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