| Equity [Abstract] | Period [Axis] |
|---|
2016-01-01 - 2016-12-31 |
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Equity [Abstract] | |
Schedule of Warrant Disclosures | As of December 31, 2016, the Company had outstanding warrants to purchase shares of common stock as follows (in thousands, except per share data): | | | | | | | | | Expiration Date | | Exercise Price | | Warrants Outstanding at December 31, 2016 | October 2023 | | $ | 5.76 |
| | 13 |
| February 2024 | | $ | 10.12 |
| | 119 |
| Total | | | | 132 |
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The table below is a summary of the Company’s common stock warrant activity during the year ended December 31, 2016 (in thousands, except per share data). | | | | | | | | | | | Shares | | Weighted
Average
Exercise
Price | Outstanding as of December 31, 2015 | | 191 |
| | $ | 9.96 |
| Issued | | — |
| | — |
| Exercised | | — |
| | — |
| Canceled | | (59 | ) | (1) | $ | 10.31 |
| Outstanding as of December 31, 2016 | | 132 |
| | $ | 9.80 |
| | | | | |
(1) In February 2016, warrants to purchase 59,288 shares of common stock issuable pertaining to the undrawn $10.0 million under the 2014 Loan and Security Agreement did not vest and were no longer exercisable, and were therefore canceled (See Note 6). |
Schedule of Valuation Assumptions, Warrants | | | | | | | | | | | | | | IPO Date April 3, 2014 | | December 31, 2013 | | Fair value of Series A-2 preferred stock | | $ | 1.75 |
| (1) | $ | 2.69 |
| (2) | Fair value of Series D-2 preferred stock | | $ | 1.75 |
| (1) | $ | 2.81 |
| (2) | Fair value of common stock | | $ | 7.00 |
| (1) | * | | Risk-free interest rate | | 0.13% to 2.73% | | 0.33% to 2.60% | | Expected life | | Remaining
contractual life | | Remaining
contractual life | | Expected dividends | | — | | — | | Volatility | | 40% - 50% | | 45 % | | | | | | | | | | | | | | (1) Fair value of the underlying stock is based on the Company's IPO price of $7.00 per share calculated on a pre-reverse split basis for preferred stock and post-reverse split basis for common stock. | (2) The per share data is on a pre-reverse split basis for preferred stock. | * There were no liability-classified common stock warrants at December 31, 2013. |
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Schedule of Common Stock Reserved for Future Issuance | As of December 31, 2016, shares of common stock reserved for future issuance related to outstanding equity awards, warrants, and employee equity incentive plans were as follows (in thousands): | | | | | | | December 31, 2016 | Stock options outstanding | | 5,556 |
| Restricted stock units outstanding | | 2,019 |
| Shares available for future grant under 2014 Plan | | 6,095 |
| Shares available for future issuance under ESPP | | 1,102 |
| Common stock warrants outstanding | | 132 |
| Total shares of common stock reserved | | 14,904 |
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Schedule of Stock Option Activities | A summary of the Company’s stock option activity during the year ended December 31, 2016 is as follows (in thousands, except years and per share data): | | | | | | | | | | | | | | | | | Number of Shares | | Weighted
Average
Exercise
Price | | Weighted Average Remaining Contractual Life (Years) | | Aggregate
Intrinsic
Value (1) | Outstanding as of December 31, 2015 | | 6,092 |
| | $ | 4.58 |
| | | | | Options granted | | 867 |
| | 9.48 |
| | | | | Options exercised | | (982 | ) | | 4.37 |
| | | | | Options forfeited or expired | | (421 | ) | | 6.56 |
| | | | | Outstanding as of December 31, 2016 | | 5,556 |
| | $ | 5.23 |
| | 5.9 | | $ | 49,895 |
| Vested and expected to vest as of December 31, 2016 | | 5,489 |
| | 5.18 |
| | 5.9 | | 49,570 |
| Exercisable as of December 31, 2016 | | 4,065 |
| | 4.13 |
| | 5.0 | | 40,996 |
| | | | | | | | | | | | | | | | | | | (1) The aggregate intrinsic value amounts are computed based on the difference between the exercise price of the stock options and the fair market value of the Company’s common stock of $14.19 per share as of December 31, 2016 for all in-the-money stock options outstanding. |
Following is additional information pertaining to the Company’s stock option activities (in thousands, except per share data): | | | | | | | | | | | | | | | | Year Ended December 31, | | | 2016 | | 2015 | | 2014 | Weighted-average grant date fair value per share of options granted | | $ | 4.50 |
| | $ | 2.38 |
| | $ | 3.42 |
| Intrinsic value of options exercised (1) | | 5,865 |
| | 3,233 |
| | 9,808 |
| Proceeds received from options exercised | | 4,286 |
| | 1,268 |
| | 1,127 |
| | | | | | | | | | | | | | | (1) Intrinsic value of options exercised is the difference between the fair market value of the Company’s common stock at the time of exercise and the exercise price paid. |
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Schedule of RSU Activities | A summary of RSU activity during the year ended December 31, 2016 is as follows (in thousands, except years and per share data): | | | | | | | | | | | Number of Shares | | Weighted Average Grant Date Fair Value Per Share | Outstanding as of December 31, 2015 | | 1,818 |
| | $ | 5.01 |
| RSUs granted | | 1,308 |
| | 9.71 |
| RSUs vested and released | | (896 | ) | | 5.59 |
| RSUs forfeited | | (211 | ) | | 6.47 |
| Outstanding as of December 31, 2016 | | 2,019 |
| | $ | 7.65 |
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Schedule of Stock-based Compensation Expense | Stock-based compensation expenses for the years ended December 31, 2016, 2015 and 2014 were as follows (in thousands): | | | | | | | | | | | | | | | | Year Ended December 31, | | | 2016 | | 2015 | | 2014 | Cost of revenue | | $ | 1,375 |
| | $ | 866 |
| | $ | 542 |
| Research and development | | 2,059 |
| | 1,790 |
| | 1,931 |
| Sales and marketing | | 2,363 |
| | 1,800 |
| | 1,510 |
| General and administrative | | 3,846 |
| | 3,274 |
| | 2,770 |
| Total stock-based compensation | | $ | 9,643 |
| | $ | 7,730 |
| | $ | 6,753 |
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As of December 31, 2016, unrecognized stock-based compensation expense by award type, net of estimated forfeitures, and their expected weighted-average recognition periods are summarized in the following table (in thousands, except years). | | | | | | | | | | | | | | | | Stock Option | | RSU | | ESPP | Unrecognized stock-based compensation expense | | $ | 5,722 |
| | $ | 12,619 |
| | $ | 409 |
| Weighted-average amortization period | | 2.4 years |
| | 2.9 years |
| | 0.4 years |
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Schedule of Valuation Assumptions, Stock Option and ESPP | The weighted-average assumptions used to value stock options and purchase rights under the ESPP granted during the years ended December 31, 2016, 2015 and 2014 were as follows: | | | | | | | | Stock Options | | Year Ended December 31, | | | 2016 | | 2015 | | 2014 | Expected term (years) | | 5.7 | | 6.1 | | 6.1 | Volatility | | 46% | | 49% | | 55% | Risk-free interest rate | | 1.4% | | 1.6% | | 1.8% | Dividend yield | | — | | — | | — |
| | | | | | | | | | | | | | ESPP | | Granted In | | | November 2016 | | May 2016 | | November 2015 | | May 2015 | | November 2014 | | April 2014 | Expected term (years) | | 0.5 | | 0.5 | | 0.5 | | 0.5 | | 0.5 | | 0.8 | Volatility | | 42% | | 58% | | 54% | | 43% | | 56% | | 39% | Risk-free interest rate | | 0.6% | | 0.4% | | 0.3% | | 0.1% | | 0.1% | | 0.1% | Dividend yield | | — | | — | | — | | — | | — | | — |
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