Annual report pursuant to Section 13 and 15(d)

Income Taxes - Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits (Detail)

v2.4.1.9
Income Taxes - Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Income Tax Disclosure [Abstract]    
Beginning balance $ 1,241,781us-gaap_UnrecognizedTaxBenefits $ 880,638us-gaap_UnrecognizedTaxBenefits
Additions based on tax positions related to the current year 112,871us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions 361,143us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions
Additions for the tax positions of prior years 0us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions 0us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions
Reductions for the tax positions of prior years 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions
Ending balance $ 1,354,652us-gaap_UnrecognizedTaxBenefits $ 1,241,781us-gaap_UnrecognizedTaxBenefits