Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation - Additional Information (Detail)

v2.4.1.9
Stock-based Compensation - Additional Information (Detail) (USD $)
3 Months Ended 0 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Mar. 16, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Stock option awards 900,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross  
Weighted-average grant date fair value $ 1.30us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue    
Stock options vested 6,667us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares    
Stock options forfeited 80,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod    
Number of stock options, exercised 0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised    
Non- employee Directors [Member]      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Annual retainer amount for the threshold of stock precluded from selling $ 270,000ogen_MinimumDollarValueStockOwnershipHoldingRequirementThreshold
/ us-gaap_TitleOfIndividualAxis
= ogen_NonEmployeeDirectorsMember
   
2012 Equity Incentive Plan [Member] | Chief Financial Officer [Member]      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Stock option awards     200,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_PlanNameAxis
= ogen_TwoThousandTwelveEquityIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ChiefFinancialOfficerMember
Exercise price of plan     $ 1.32us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice
/ us-gaap_PlanNameAxis
= ogen_TwoThousandTwelveEquityIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ChiefFinancialOfficerMember
Vesting period     3 years
2012 Equity Incentive Plan [Member] | Non- employee Directors [Member]      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Stock option awards     80,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_PlanNameAxis
= ogen_TwoThousandTwelveEquityIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= ogen_NonEmployeeDirectorsMember
2012 Equity Incentive Plan [Member] | Non- employee Directors [Member] | Restricted Stock [Member]      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Exercise price of plan     $ 1.32us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
/ us-gaap_PlanNameAxis
= ogen_TwoThousandTwelveEquityIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= ogen_NonEmployeeDirectorsMember
Restricted shares awarded     40,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
/ us-gaap_PlanNameAxis
= ogen_TwoThousandTwelveEquityIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= ogen_NonEmployeeDirectorsMember
Restricted shares ending date Under the Company's 2012 Plan of which 10,000 restricted shares will vest at the end of each calendar quarter in 2015 provided the recipient remains a director through the vesting date.    
Restricted shares vest in each quarter end 10,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
/ us-gaap_PlanNameAxis
= ogen_TwoThousandTwelveEquityIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= ogen_NonEmployeeDirectorsMember
   
Operations Or Product Development [Member] | 2012 Equity Incentive Plan [Member] | Senior Vice President [Member]      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Stock option awards     150,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_PlanNameAxis
= ogen_TwoThousandTwelveEquityIncentivePlanMember
/ us-gaap_ProductOrServiceAxis
= ogen_OperationsOrProductDevelopmentMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_VicePresidentMember
Exercise price of plan     $ 1.32us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice
/ us-gaap_PlanNameAxis
= ogen_TwoThousandTwelveEquityIncentivePlanMember
/ us-gaap_ProductOrServiceAxis
= ogen_OperationsOrProductDevelopmentMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_VicePresidentMember
Vesting period     3 years
Discovery Research [Member] | 2012 Equity Incentive Plan [Member] | Senior Vice President [Member]      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Stock option awards     150,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_PlanNameAxis
= ogen_TwoThousandTwelveEquityIncentivePlanMember
/ us-gaap_ProductOrServiceAxis
= ogen_DiscoveryResearchMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_VicePresidentMember
Exercise price of plan     $ 1.32us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice
/ us-gaap_PlanNameAxis
= ogen_TwoThousandTwelveEquityIncentivePlanMember
/ us-gaap_ProductOrServiceAxis
= ogen_DiscoveryResearchMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_VicePresidentMember
Vesting period     3 years