Additional number of common shares reserved for future issuance.

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- Definition

The maximum value of award or purchase a plan participant can receive under the plan per period.

+ References

No definition available.

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- Definition

The floor for the equity price in relation to the fair market value of common stock on the date of grant or offering, represented as a percentage.

+ References

No definition available.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
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- Definition

Aggregate number of common shares reserved for future issuance.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
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- Definition

Minimum period the individual is required to perform services to be fully vested under the deferred compensation arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 55
-Paragraph 7
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- Definition

The cash inflow associated with the amount received from the stock plan during the period.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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

No definition available.

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- Definition

The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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- Definition

The highest quantity of shares an employee can purchase under the plan per period.

+ References

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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- Definition

Maximum number of shares that may be issued in accordance with the plan as a proportion of outstanding capital stock.

+ References

No definition available.

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- Definition

Number of options vested.

+ References

No definition available.

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- Definition

Number of shares issued during the period as a result of an employee stock purchase plan.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
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Stock-Based Compensation (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended	9 Months Ended
Stock-Based Compensation (Details) - USD ($)	Jun. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Apr. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Jun. 30, 2015
Stock Based Compensation
Stock-based compensation expense		$ 3,616,000	$ 2,986,000
Chief Executive Officer
Stock Based Compensation
Stock option shares approved	425,000
2015 Plan
Stock Based Compensation
Shares reserved for issuance								3,451,495
Additional shares reserved for issuance								9,890,310
Employee stock purchase plan
Stock Based Compensation
Issuance of common stock under employee stock purchase plan (in shares)				206,447
Proceeds from issuance of common stock under employee stock purchase plan				$ 1,900,000
Performance-based awards \| Chief Executive Officer
Stock Based Compensation
Stock option shares approved	200,000
Requisite service period	3 years
Stock-based compensation expense		$ 100,000			$ 400,000
Performance-based awards \| First Vesting Milestone \| Chief Executive Officer
Stock Based Compensation
Number of options vested	50,000
Vesting period	1 year
Performance-based awards \| Second Vesting Milestone \| Chief Executive Officer
Stock Based Compensation
Number of options vested	75,000
Vesting period	1 year
Performance-based awards \| Third Vesting Milestone \| Chief Executive Officer
Stock Based Compensation
Number of options vested	75,000
Vesting period	1 year
Employee and non-employee stock options
Stock Based Compensation
Stock-based compensation expense					$ 10,138,000	$ 8,406,000
Shares available for issuance		5,961,000			5,961,000		4,737,000
Restricted stock units
Stock Based Compensation
Shares granted					923,000
2015 Employee Stock Purchase Plan
Stock Based Compensation
Shares reserved for issuance		893,548			893,548
Shares reserved for issuance as a proportion common stock outstanding (as a percent)					1.00%
Price in relation to fair market value of common stock on the date of grant, lower range limit (as a percent)					85.00%
Maximum number of shares a participant may receive during the period (in shares)					5,000
Maximum amount of award or purchase during a calendar year					$ 25,000
Maximum employee contribution of employee's cash compensation (as a percent)		15.00%			15.00%
2015 Employee Stock Purchase Plan \| Minimum
Stock Based Compensation
Shares reserved for issuance		880,000			880,000