Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements and Marketable Securities - Schedule of Assumptions used in Estimating Common and Preferred Stock Warrant Liability (Details)

v2.4.1.9
Fair Value Measurements and Marketable Securities - Schedule of Assumptions used in Estimating Common and Preferred Stock Warrant Liability (Details) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Common Stock    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Estimated fair value of common share $ 0.80us-gaap_SharePrice
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
$ 5.75us-gaap_SharePrice
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Weighted-average risk free interest rate 1.53%us-gaap_FairValueAssumptionsRiskFreeInterestRate
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
1.26%us-gaap_FairValueAssumptionsRiskFreeInterestRate
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Weighted-average expected life (in years) 4 years 8 months 12 days 4 years 1 month 6 days
Expected dividend yield 0.00%us-gaap_FairValueAssumptionsExpectedDividendRate
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
0.00%us-gaap_FairValueAssumptionsExpectedDividendRate
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Weighted average expected volatility 116.00%us-gaap_FairValueAssumptionsWeightedAverageVolatilityRate
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
47.00%us-gaap_FairValueAssumptionsWeightedAverageVolatilityRate
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
Preferred Stock    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Estimated fair value of common share   $ 5.75us-gaap_SharePrice
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_PreferredStockMember
Weighted-average risk free interest rate   1.11%us-gaap_FairValueAssumptionsRiskFreeInterestRate
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_PreferredStockMember
Weighted-average expected life (in years)   3 years 7 months 6 days
Expected dividend yield   0.00%us-gaap_FairValueAssumptionsExpectedDividendRate
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_PreferredStockMember
Weighted average expected volatility   44.00%us-gaap_FairValueAssumptionsWeightedAverageVolatilityRate
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_PreferredStockMember