Quarterly report pursuant to Section 13 or 15(d)

Earnings (Loss) Per Share (Narrative) (Details)

v2.4.1.9
Earnings (Loss) Per Share (Narrative) (Details)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Stock Options Warrants Convertible Debt And Convertible Preferred Stock    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Shares excluded in determining basic and diluted loss per share 20,100us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= navb_StockOptionsWarrantsConvertibleDebtAndConvertiblePreferredStockMember
19,200us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= navb_StockOptionsWarrantsConvertibleDebtAndConvertiblePreferredStockMember
Unvested Restricted Stock    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Shares excluded in determining basic and diluted loss per share 672us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= us-gaap_RestrictedStockUnitsRSUMember
605us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= us-gaap_RestrictedStockUnitsRSUMember