Share-Based Compensation (Details 1) $ / shares in Units, $ in Thousands	9 Months Ended
Sep. 30, 2018 USD ($) $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Outstanding \| shares	344,055
Number of Shares, Granted \| shares	926,931
Number of Shares, Exercised \| shares	(62,224)
Number of Shares, Forfeited/cancelled \| shares	(130,579)
Number of Shares, Outstanding \| shares	1,078,183
Number of Shares, Exercisable – September 30, 2018 \| shares	168,360
Number of Shares, Exercisable and expected to vest – September 30, 2018 \| shares	1,078,183
Weighted-Average Exercise Price, Outstanding \| $ / shares	$ 8.70
Weighted-Average Exercise Price, Granted \| $ / shares	8.47
Weighted-Average Exercise Price, Exercised \| $ / shares	5.34
Weighted-Average Exercise Price, Forfeited/cancelled \| $ / shares	17.45
Weighted-Average Exercise Price, Outstanding \| $ / shares	7.64
Weighted-Average Exercise Price, Exercisable – September 30, 2018 \| $ / shares	3.95
Weighted-Average Exercise Price, Exercisable and expected to vest – September 30, 2018 \| $ / shares	$ 7.64
Weighted-Average Remaining Contractual Term (Years), Outstanding - September 30, 2018	9 years 3 months 14 days
Weighted-Average Remaining Contractual Term (Years), Exercisable - September 30, 2018	6 years 6 months 25 days
Weighted-Average Remaining Contractual Term (Years), Exercisable and expected to vest – September 30, 2018	9 years 3 months 14 days
Aggregate Intrinsic Value, Outstanding – September 30, 2018 \| $	$ 1,386
Aggregate Intrinsic Value, Exercisable – September 30, 2018 \| $	832
Aggregate Intrinsic Value, Exercisable and expected to vest – Septemberr 30, 2018 \| $	$ 1,386

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of fully vested and expected to vest exercisable options that may be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for fully vested and expected to vest exercisable or convertible options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of share options (or share units) exercised during the current period.

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