Common stock shares to be issued, value.

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- Definition

Common stock weighted average price per share.

+ References

No definition available.

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- Definition

Entity public float, one third value limit.

+ References

No definition available.

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- Definition

Legal accounting and filing fees.

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No definition available.

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- Definition

Public float.

+ References

No definition available.

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- Definition

Carrying value as of the balance sheet date of obligations incurred and payable for statutory payroll taxes incurred through that date and withheld from employees pertaining to services received from them, including entity's matching share of the employees FICA taxes and contributions to the state and federal unemployment insurance programs. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Current Liabilities

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-Publisher FASB

-Name Accounting Standards Codification

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-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.20)

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- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

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-Subparagraph (SX 210.5-02.29)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 30

-Article 5

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- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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-Topic 505

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-Topic 505

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-Topic 210

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 30

-Article 5

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

The cash inflow from the additional capital contribution to the entity.

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585

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- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

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Stockholders' Equity - Additional Information (Detail) (USD $)	3 Months Ended	1 Months Ended
	Mar. 31, 2015	Apr. 30, 2015	Dec. 31, 2014	Nov. 13, 2014	Nov. 11, 2014
Sale Of Stock [Line Items]
Common stock, shares issued	6,198,967us-gaap_CommonStockSharesIssued		6,112,091us-gaap_CommonStockSharesIssued
Proceeds from issuance of common stock, net	$ 531,620
Legal, Accounting and Filing Fees	138,000evok_LegalAccountingAndFilingFees
Common stock, shares outstanding	6,198,967us-gaap_CommonStockSharesOutstanding		6,112,091us-gaap_CommonStockSharesOutstanding
Payroll withholdings from employees	111,000us-gaap_AccruedPayrollTaxesCurrent
Unrecognized compensation costs	3,200,000
Weighted average period	1 year 6 months
Employee stock purchase plan [Member]
Sale Of Stock [Line Items]
Common stock, shares issued	23,288
Sales Agreement with MLV & Co. LLC [Member]
Sale Of Stock [Line Items]
Common stock, value of shares issuable				6,600,000
Common stock, shares issued	63,588
Common stock , weighted average price per share	$ 6.85
Proceeds from issuance of common stock, net	421,000
Common stock, shares outstanding					2,900,000
Entity public float					20,000,000
Common stock, closing price					$ 6.86
One third value of entity public float					6,600,000
Sales Agreement with MLV & Co. LLC [Member] \| Subsequent Event [Member]
Sale Of Stock [Line Items]
Common stock, value of shares issuable		5,600,000
Common stock, shares issued		69,843
Common stock , weighted average price per share		$ 7.60
Proceeds from issuance of common stock, net		$ 515,000