v3.8.0.1
Revenue - Impact of Topic 606 (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
Apr. 01, 2017
Dec. 30, 2017
Balance Sheet Related Disclosures [Abstract]      
Other non-current assets $ 2,434   $ 2,066
Total assets 200,032   184,376
Deferred revenue [1] 23,201   18,626
Total current liabilities 44,113   37,585
Other non-current liabilities 5,980   5,779
Total liabilities 52,317   44,656
Accumulated deficit (174,315)   (177,145)
Total stockholders' equity 96,776   89,461
Total liabilities, redeemable convertible preferred stock, and stockholders' equity 200,032   $ 184,376
Income Statement [Abstract]      
Revenue [2] 47,325 $ 43,366  
Selling and marketing [3] 16,857 19,197  
Total operating expenses 36,492 33,865  
Operating income 1,390 735  
Income before income taxes 1,952 1,036  
Net income 2,697 $ 824  
Difference between Revenue Guidance in Effect before and after Topic 606      
Balance Sheet Related Disclosures [Abstract]      
Other non-current assets 347    
Total assets 347    
Deferred revenue 288    
Total current liabilities 288    
Total liabilities 288    
Accumulated deficit 59    
Total stockholders' equity 59    
Total liabilities, redeemable convertible preferred stock, and stockholders' equity 347    
Income Statement [Abstract]      
Revenue 47,494    
Selling and marketing 16,952    
Total operating expenses 36,587    
Operating income 1,464    
Income before income taxes 2,026    
Net income 2,771    
Calculated under Revenue Guidance in Effect before Topic 606      
Balance Sheet Related Disclosures [Abstract]      
Other non-current assets 2,087    
Total assets 199,685    
Deferred revenue 22,913    
Total current liabilities 43,825    
Total liabilities 52,029    
Accumulated deficit (174,374)    
Total stockholders' equity 96,717    
Total liabilities, redeemable convertible preferred stock, and stockholders' equity 199,685    
Income Statement [Abstract]      
Revenue 169    
Selling and marketing 95    
Total operating expenses 95    
Operating income 74    
Income before income taxes 74    
Net income $ 74    
[1] (5) Includes deferred revenue associated with related party of $138 and $2 at March 31, 2018 and December 30, 2017, respectively (Note 14)
[2] (1) Includes related party revenue of $637 and $392 for the three months ended March 31, 2018 and April 1, 2017, respectively. (Note 14)
[3] (2) Includes related party expenses of $3,036 and $3,699 for the three months ended March 31, 2018 and April 1, 2017, respectively. (Note 14)