Revenue - Impact of Topic 606 (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Jun. 30, 2018 |
Jul. 01, 2017 |
Jun. 30, 2018 |
Jul. 01, 2017 |
Dec. 30, 2017 |
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| Revenue, Initial Application Period Cumulative Effect Transition [Line Items] | ||||||||||||
| Other non-current assets | $ 2,708 | $ 2,708 | $ 2,066 | |||||||||
| Total assets | 203,163 | 203,163 | 184,376 | |||||||||
| Deferred revenue | [1] | 21,579 | 21,579 | 18,626 | ||||||||
| Total current liabilities | 41,034 | 41,034 | 37,585 | |||||||||
| Other non-current liabilities | 6,347 | 6,347 | 5,779 | |||||||||
| Total liabilities | 49,136 | 49,136 | 44,656 | |||||||||
| Accumulated deficit | (174,484) | (174,484) | (177,145) | |||||||||
| Total stockholders' equity | 102,423 | 102,423 | 89,461 | |||||||||
| Total liabilities, redeemable convertible preferred stock and stockholders' equity | 203,163 | 203,163 | $ 184,376 | |||||||||
| Revenue | [2] | 45,966 | $ 41,972 | 93,291 | $ 85,338 | |||||||
| Selling and marketing | [3] | 15,901 | 17,853 | 32,758 | 37,050 | |||||||
| Total operating expenses | 36,414 | 33,375 | 72,906 | 67,240 | ||||||||
| Operating (loss) income | (271) | (403) | 1,119 | 332 | ||||||||
| (Loss) income before income taxes | (1,039) | 605 | 913 | 1,641 | ||||||||
| Net (loss) income | (169) | $ 1,673 | 2,528 | $ 2,497 | ||||||||
| Calculated under Revenue Guidance in Effect before Topic 606 | ||||||||||||
| Revenue, Initial Application Period Cumulative Effect Transition [Line Items] | ||||||||||||
| Other non-current assets | 2,077 | 2,077 | ||||||||||
| Total assets | 202,532 | 202,532 | ||||||||||
| Deferred revenue | 21,335 | 21,335 | ||||||||||
| Total current liabilities | 40,790 | 40,790 | ||||||||||
| Other non-current liabilities | 6,169 | 6,169 | ||||||||||
| Total liabilities | 48,714 | 48,714 | ||||||||||
| Accumulated deficit | (174,693) | (174,693) | ||||||||||
| Total stockholders' equity | 102,214 | 102,214 | ||||||||||
| Total liabilities, redeemable convertible preferred stock and stockholders' equity | 202,532 | 202,532 | ||||||||||
| Revenue | [2] | 46,100 | 93,594 | |||||||||
| Selling and marketing | [3] | 16,185 | 33,137 | |||||||||
| Total operating expenses | 36,698 | 73,285 | ||||||||||
| Operating (loss) income | (421) | 1,043 | ||||||||||
| (Loss) income before income taxes | (1,189) | 837 | ||||||||||
| Net (loss) income | (319) | 2,452 | ||||||||||
| Difference between Revenue Guidance in Effect before and after Topic 606 | ||||||||||||
| Revenue, Initial Application Period Cumulative Effect Transition [Line Items] | ||||||||||||
| Other non-current assets | 631 | 631 | ||||||||||
| Total assets | 631 | 631 | ||||||||||
| Deferred revenue | 244 | 244 | ||||||||||
| Total current liabilities | 244 | 244 | ||||||||||
| Other non-current liabilities | 178 | 178 | ||||||||||
| Total liabilities | 422 | 422 | ||||||||||
| Accumulated deficit | 209 | 209 | ||||||||||
| Total stockholders' equity | 209 | 209 | ||||||||||
| Total liabilities, redeemable convertible preferred stock and stockholders' equity | 631 | 631 | ||||||||||
| Revenue | [2] | 134 | 303 | |||||||||
| Selling and marketing | [3] | 284 | 379 | |||||||||
| Total operating expenses | 284 | 379 | ||||||||||
| Operating (loss) income | (150) | (76) | ||||||||||
| (Loss) income before income taxes | (150) | (76) | ||||||||||
| Net (loss) income | $ (150) | $ (76) | ||||||||||
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