Net Loss Per Common Share (Tables)
 6 Months Ended
Jun. 27, 2020
Earnings Per Share [Abstract]  
Schedule of net income (loss) per share
The following table sets forth the computation of basic and diluted net loss per common share for the periods indicated (in thousands, except per share data):
 Three Months EndedSix Months Ended
June 27,
2020		June 29,
2019		June 27,
2020		June 29,
2019
Numerator:
Net loss$(4,212) $(5,045) $(11,156) $(14,812) 
Denominator:
Weighted-average common shares outstanding used to compute basic net loss per share57,261  54,624  56,906  54,339  
Basic and diluted net loss per common share$(0.07) $(0.09) $(0.20) $(0.27) 
Potentially dilutive shares, weighted average6,996  7,191  6,789  6,832