XML 28 R71.htm IDEA: XBRL DOCUMENT v2.4.1.9
Stock-based Compensation - Assumptions used to Estimate Fair Value of Share-based Payment Awards (Detail)
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Schedule of Stock-based Compensation Details Fair Value of Share Based Payment Awards [Line Items]    
Expected term 4 years  
Expected dividend yield 0.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate 0.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
Minimum [Member]    
Schedule of Stock-based Compensation Details Fair Value of Share Based Payment Awards [Line Items]    
Risk-free interest rate 1.68%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
 
Expected volatility 141.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
 
Maximum [Member]    
Schedule of Stock-based Compensation Details Fair Value of Share Based Payment Awards [Line Items]    
Risk-free interest rate 2.24%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
 
Expected volatility 142.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate
/ us-gaap_RangeAxis
= us-gaap_MaximumMember