Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Summary of Cash and Cash Equivalents and Short Term Investments (Detail)

v2.4.1.9
Fair Value Measurements - Summary of Cash and Cash Equivalents and Short Term Investments (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]        
Cash, amortized cost and estimated fair value $ 16,481us-gaap_Cash $ 10,575us-gaap_Cash    
Cash and cash equivalents, amortized cost and estimated fair value 27,897us-gaap_CashAndCashEquivalentsAtCarryingValue 14,593us-gaap_CashAndCashEquivalentsAtCarryingValue 18,075us-gaap_CashAndCashEquivalentsAtCarryingValue 28,517us-gaap_CashAndCashEquivalentsAtCarryingValue
Restricted cash, amortized cost and estimated fair value 251us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue      
Amortized Cost 19,179us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis 24,627us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis    
Gross Unrealized Gains 1us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax 3us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax    
Gross Unrealized Losses (20)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax (1)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax    
Estimated Fair Value 19,160us-gaap_AvailableForSaleSecuritiesDebtSecurities 24,629us-gaap_AvailableForSaleSecuritiesDebtSecurities    
Restricted cash, amortized cost and estimated fair value   314us-gaap_RestrictedCashAndCashEquivalentsNoncurrent    
Money market securities [Member]        
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]        
Cash equivalents, amortized cost and estimated fair value 11,416us-gaap_CashEquivalentsAtCarryingValue
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_MoneyMarketFundsMember
4,018us-gaap_CashEquivalentsAtCarryingValue
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_MoneyMarketFundsMember
   
Restricted cash, amortized cost and estimated fair value 251us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_MoneyMarketFundsMember
     
Restricted cash, amortized cost and estimated fair value   314us-gaap_RestrictedCashAndCashEquivalentsNoncurrent
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_MoneyMarketFundsMember
   
Corporate bonds and commercial paper [Member]        
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]        
Amortized Cost 19,179us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_FairValueByAssetClassAxis
= ogxi_CorporateBondsAndCommercialPaperShortTermMember
24,627us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_FairValueByAssetClassAxis
= ogxi_CorporateBondsAndCommercialPaperShortTermMember
   
Gross Unrealized Gains 1us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_FairValueByAssetClassAxis
= ogxi_CorporateBondsAndCommercialPaperShortTermMember
3us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_FairValueByAssetClassAxis
= ogxi_CorporateBondsAndCommercialPaperShortTermMember
   
Gross Unrealized Losses (20)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_FairValueByAssetClassAxis
= ogxi_CorporateBondsAndCommercialPaperShortTermMember
(1)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_FairValueByAssetClassAxis
= ogxi_CorporateBondsAndCommercialPaperShortTermMember
   
Estimated Fair Value $ 19,160us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_FairValueByAssetClassAxis
= ogxi_CorporateBondsAndCommercialPaperShortTermMember
$ 24,629us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_FairValueByAssetClassAxis
= ogxi_CorporateBondsAndCommercialPaperShortTermMember