Annual report pursuant to Section 13 and 15(d)

INVESTMENT SECURITIES (Details)

v2.4.1.9
INVESTMENT SECURITIES (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Investment securities      
Amortized Cost $ 2,118us-gaap_AvailableForSaleSecuritiesAmortizedCost $ 1,627us-gaap_AvailableForSaleSecuritiesAmortizedCost  
Gross Unrealized Gains 455natr_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax 398natr_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax  
Gross Unrealized Losses (27)natr_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax (19)natr_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax  
Fair Value 2,546us-gaap_AvailableForSaleSecurities 2,006us-gaap_AvailableForSaleSecurities  
Proceeds from the sales of available-for-sale securities 247us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities 200us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities 3,789us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities
Gross realized gains (losses) on sales of available-for-sale securities (net of tax) 0us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet 0us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet 0us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet
Municipal obligations      
Investment securities      
Amortized Cost 100us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
403us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
 
Gross Unrealized Gains 1natr_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
12natr_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
 
Fair Value 101us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
415us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
 
Municipal obligations | Maximum      
Investment securities      
Maturity period 2 years    
U.S. government security funds      
Investment securities      
Amortized Cost 1,791us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentDebtSecuritiesMember
997us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentDebtSecuritiesMember
 
Gross Unrealized Losses (15)natr_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentDebtSecuritiesMember
(14)natr_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentDebtSecuritiesMember
 
Fair Value 1,776us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentDebtSecuritiesMember
983us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentDebtSecuritiesMember
 
Equity securities      
Investment securities      
Amortized Cost 227us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
227us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
 
Gross Unrealized Gains 454natr_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
386natr_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
 
Gross Unrealized Losses (12)natr_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
(5)natr_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
 
Fair Value $ 669us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
$ 608us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember