Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Additional Information (Detail)

v2.4.1.9
Fair Value Measurements - Additional Information (Detail) (USD $)
In Thousands, except Share data, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Dec. 31, 2014
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Warrant liability $ 2,537us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue $ 3,002us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
Maximum maturity period of cash and cash equivalents 90 days  
Maximum maturity period of short-term investments 1 year  
Series A and Series B Warrants issued in July 2014 Financing    
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Warrants outstanding and exercisable 0us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_ClassOfWarrantOrRightAxis
= ogxi_SeriesAAndSeriesBWarrantsMember 		 
Maximum    
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Maturity period of securities 1 year