Quarterly report pursuant to Section 13 or 15(d)

Stock Warrants (Narrative) (Details)

v2.4.1.9
Stock Warrants (Narrative) (Details) (USD $)
Mar. 31, 2015
Class of Warrant or Right [Line Items]  
Warrants outstanding (shares) 1,800,000us-gaap_ClassOfWarrantOrRightOutstanding
Common Stock  
Class of Warrant or Right [Line Items]  
Exercise price of warrant issued, dollars per share 2,000us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonStockMember
Common Stock | Macrophage Therapeutics  
Class of Warrant or Right [Line Items]  
Number of shares underlying warrant issued 300us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ dei_LegalEntityAxis
= navb_MacrophageTherapeuticsMember
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonStockMember
Minimum  
Class of Warrant or Right [Line Items]  
Exercise price of warrant issued, dollars per share 1.918us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Maximum  
Class of Warrant or Right [Line Items]  
Exercise price of warrant issued, dollars per share 3.04us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
Weighted Average  
Class of Warrant or Right [Line Items]  
Exercise price of warrant issued, dollars per share 2.27us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_RangeAxis
= us-gaap_WeightedAverageMember