General form of registration statement for all companies including face-amount certificate companies

Stock-Based Compensation - Schedule of Weighted-Average Assumptions Used for Calculating Value of Options Granted (Detail)

v2.4.1.9
Stock-Based Compensation - Schedule of Weighted-Average Assumptions Used for Calculating Value of Options Granted (Detail)
12 Months Ended
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Dividend yield 0.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
Expected volatility 74.66%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate
Weighted average risk-free interest rate 1.77%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
Minimum [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Expected term 5 years 7 months 6 days
Maximum [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Expected term 5 years 9 months 18 days