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Fair Value Measurements - Assumption Used to Determine Fair Value of Warrant Liability (Detail)
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3 Months Ended | 12 Months Ended |
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Mar. 31, 2015
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Dec. 31, 2014
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| Fair Value Disclosures [Abstract] | ||
| Expected volatility | 74.10%us-gaap_FairValueAssumptionsExpectedVolatilityRate | 74.80%us-gaap_FairValueAssumptionsExpectedVolatilityRate |
| Remaining contractual term (in years) | 4 years 5 months 1 day | 4 years 8 months 1 day |
| Risk-free interest rate | 1.37%us-gaap_FairValueAssumptionsRiskFreeInterestRate | 1.65%us-gaap_FairValueAssumptionsRiskFreeInterestRate |
| Expected dividend yield | 0.00%us-gaap_FairValueAssumptionsExpectedDividendRate | 0.00%us-gaap_FairValueAssumptionsExpectedDividendRate |
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- Definition
Fair Value Assumptions, Remaining Contractual Term No definition available.
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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). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Risk-free interest rate assumption used in valuing an instrument. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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