Warrants - Fair Value of Warrant to Purchase Shares (Detail) (Warrants to Purchase Series B Preferred Stock [Member], USD $)	12 Months Ended
Dec. 31, 2013
Warrants to Purchase Series B Preferred Stock [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value of underlying instrument	$ 0.95
Expected volatility	82.00%
Expected term (in years)	5 years 11 months 5 days
Risk-free interest rate	1.10%
Expected dividend yield	0.00%

Fair value inputs comparable share price.

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- Definition

Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

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- Definition

Risk-free interest rate assumption used in valuing an instrument.

+ References

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