Annual report pursuant to Section 13 and 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
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2012
Dec. 31, 2013
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]      
Warrant liability $ 3,002us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue   $ 214us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
Maximum maturity period of cash and cash equivalents 90 days    
Maximum maturity period of short-term investments 1 year 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 3,500,000us-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