Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Narrative) (Details)

v2.4.1.9
Stock-Based Compensation (Narrative) (Details) (USD $)
3 Months Ended
Mar. 31, 2015
plan
Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of stock based compensation plans 2navb_NumberOfStockBasedCompensationPlans  
Stock compensation expense $ 1,106,824us-gaap_ShareBasedCompensation $ 693,203us-gaap_ShareBasedCompensation
The 2002 Plan    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total number of shares authorized 12,000,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
/ us-gaap_PlanNameAxis
= navb_The2002StockIncentivePlanMember
 
The 2014 Plan    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total number of shares authorized 5,000,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
/ us-gaap_PlanNameAxis
= navb_The2014PlanMember
 
The 2002 and 2014 Plan    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock based compensation, outstanding stock options' expiration period 10 years  
Stock based compensation, outstanding stock options' expiration period upon optionee's separation from employment 90 days  
The 2002 and 2014 Plan | Minimum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock based compensation, granted stock options' vesting period 1 year  
The 2002 and 2014 Plan | Maximum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock based compensation, granted stock options' vesting period 4 years