v3.10.0.1
Revenue - Impact of Topic 606 (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 29, 2018
Sep. 30, 2017
Sep. 29, 2018
Sep. 30, 2017
Dec. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]          
Other non-current assets $ 3,017   $ 3,017   $ 2,066
Total assets 218,427   218,427   184,376
Deferred revenue [1] 22,131   22,131   18,626
Total current liabilities 48,348   48,348   37,585
Other non-current liabilities 6,562   6,562   5,779
Total liabilities 56,701   56,701   44,656
Accumulated deficit (172,632)   (172,632)   (177,145)
Total stockholders' equity 109,404   109,404   89,461
Total liabilities, redeemable convertible preferred stock and stockholders' equity 218,427   218,427   $ 184,376
Revenue [2] 49,160 $ 44,536 142,451 $ 129,874  
Selling and marketing [3] 16,439 17,749 49,197 54,799  
Total operating expenses 36,791 36,188 109,697 103,428  
Operating income (loss) 837 (997) 1,956 (665)  
(Loss) income before income taxes 875 (385) 1,788 1,256  
Net income 1,852 $ 262 4,380 $ 2,759  
Calculated under Revenue Guidance in Effect before Topic 606          
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]          
Other non-current assets 2,127   2,127    
Total assets 217,537   217,537    
Deferred revenue 21,819   21,819    
Total current liabilities 48,036   48,036    
Other non-current liabilities 6,308   6,308    
Total liabilities 56,135   56,135    
Accumulated deficit (172,956)   (172,956)    
Total stockholders' equity 109,080   109,080    
Total liabilities, redeemable convertible preferred stock and stockholders' equity 217,537   217,537    
Revenue [2] 49,304   142,898    
Selling and marketing [3] 16,698   49,835    
Total operating expenses 37,050   110,335    
Operating income (loss) 722   1,765    
(Loss) income before income taxes 760   1,597    
Net income 1,737   4,189    
Difference between Revenue Guidance in Effect before and after Topic 606          
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]          
Other non-current assets 890   890    
Total assets 890   890    
Deferred revenue 312   312    
Total current liabilities 312   312    
Other non-current liabilities 254   254    
Total liabilities 566   566    
Accumulated deficit 324   324    
Total stockholders' equity 324   324    
Total liabilities, redeemable convertible preferred stock and stockholders' equity 890   890    
Revenue [2] 144   447    
Selling and marketing [3] 259   638    
Total operating expenses 259   638    
Operating income (loss) (115)   (191)    
(Loss) income before income taxes (115)   (191)    
Net income $ (115)   $ (191)    
[1] (5) Includes deferred revenue associated with related party of $47 and $2 at September 29, 2018 and December 30, 2017, respectively (Note 14)
[2] (1) Includes related party revenue of $819 and $457 for the three months ended September 29, 2018 and September 30, 2017, respectively. Includes related party revenue of $2,161 and $1,281 for the nine months ended September 29, 2018 and September 30, 2017, respectively. (Note 14)
[3] (2) Includes related party expenses of $2,912 and $3,655 for the three months ended September 29, 2018 and September 30, 2017, respectively. Includes related party expenses of $8,565 and $11,475 for the nine months ended September 30, 2018 and September 30, 2017, respectively. (Note 14)