Stock Option Plan - Summary of Stock Options Outstanding and Exercisable by Exercise Price (Details) - $ / shares	9 Months Ended
Sep. 30, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options Outstanding, Number Outstanding	1,193,602
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	7 years 9 months 18 days
Options Outstanding, Weighted-Average Exercise Price	$ 1.97	$ 1.78
Options Vested and Exercisable, Number Exercisable	377,155
Options Vested and Exercisable, Weighted-Average Exercise Price	$ 1.75
Exercise Price 0.16
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price	$ 0.16
Options Outstanding, Number Outstanding	70,000
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	5 years 3 months 18 days
Options Outstanding, Weighted-Average Exercise Price	$ 0.16
Options Vested and Exercisable, Number Exercisable	66,081
Options Vested and Exercisable, Weighted-Average Exercise Price	$ 0.16
Exercise Price 0.37
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price	$ 0.37
Options Outstanding, Number Outstanding	231,255
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	6 years 7 months 6 days
Options Outstanding, Weighted-Average Exercise Price	$ 0.37
Options Vested and Exercisable, Number Exercisable	62,663
Options Vested and Exercisable, Weighted-Average Exercise Price	$ 0.37
Exercise Price 0.97
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price	$ 0.97
Options Outstanding, Number Outstanding	159,084
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	7 years 6 months
Options Outstanding, Weighted-Average Exercise Price	$ 0.97
Options Vested and Exercisable, Number Exercisable	42,075
Options Vested and Exercisable, Weighted-Average Exercise Price	$ 0.97
Exercise Price 2.51
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price	$ 2.51
Options Outstanding, Number Outstanding	196,761
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	7 years 10 months 24 days
Options Outstanding, Weighted-Average Exercise Price	$ 2.51
Options Vested and Exercisable, Number Exercisable	60,851
Options Vested and Exercisable, Weighted-Average Exercise Price	$ 2.51
Exercise Price 2.89
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price	$ 2.89
Options Outstanding, Number Outstanding	52,000
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	8 years 4 months 24 days
Options Outstanding, Weighted-Average Exercise Price	$ 2.89
Options Vested and Exercisable, Number Exercisable	14,250
Options Vested and Exercisable, Weighted-Average Exercise Price	$ 2.89
Exercise Price 2.93
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price	$ 2.93
Options Outstanding, Number Outstanding	347,002
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	8 years 7 months 6 days
Options Outstanding, Weighted-Average Exercise Price	$ 2.93
Options Vested and Exercisable, Number Exercisable	100,820
Options Vested and Exercisable, Weighted-Average Exercise Price	$ 2.93
Exercise Price 3.18
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price	$ 3.18
Options Outstanding, Number Outstanding	137,500
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	8 years 9 months 18 days
Options Outstanding, Weighted-Average Exercise Price	$ 3.18
Options Vested and Exercisable, Number Exercisable	30,415
Options Vested and Exercisable, Weighted-Average Exercise Price	$ 3.18

Share based compensation shares authorized under stock option plans exercise price.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-SubTopic 10
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-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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