Quarterly report pursuant to Section 13 or 15(d)

Summary of Option Activity (Detail)

v2.4.1.9
Summary of Option Activity (Detail) (USD $)
 3 Months Ended 12 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Number of Shares      
Beginning Balance 3,391,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber    
Granted 2,232,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod    
Exercised (38,000)us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised    
Forfeited, cancelled, or expired (153,000)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod    
Ending Balance 5,432,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber   3,391,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Options exercisable, March 31, 2015 2,680,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber    
Vested options expired during the twelve months ended March 31, 2015 25,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod    
Weighted Average Exercise Price      
Beginning Balance $ 3.11us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice    
Granted $ 2.44us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice $ 1.86us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice  
Exercised $ 1.15us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice    
Forfeited, cancelled, or expired $ 3.44us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice    
Ending Balance $ 2.84us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice   $ 3.11us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Options exercisable, March 31, 2015 $ 3.11us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice    
Vested options expired during the twelve months ended March 31, 2015 $ 3.96us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice    
Weighted Average Remaining Contractual Term (In Years)      
Options outstanding 5 years 5 months 16 days   2 years 11 months 19 days
Options exercisable 2 years 3 months 22 days    
Aggregate Intrinsic Value      
Options outstanding $ 1,063,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue [1]    
Options outstanding 186,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue [1]   1,063,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue [1]
Options exercisable $ 183,000us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1 [1]    
[1] The intrinsic value calculation does not include negative values. This can occur when the fair market value on the reporting date is less than the exercise price of the grant.