Annual report pursuant to Section 13 and 15(d)

Note 1 - Nature of Operations and Summary of Significant Accounting Policies (Details Textual)

v2.4.1.9
Note 1 - Nature of Operations and Summary of Significant Accounting Policies (Details Textual) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Accounting Policies [Abstract]    
Inventory Valuation Reserves $ 18,000us-gaap_InventoryValuationReserves $ 0us-gaap_InventoryValuationReserves
Goodwill, Impairment Loss 0us-gaap_GoodwillImpairmentLoss 0us-gaap_GoodwillImpairmentLoss
Foreign Currency Transaction Gain (Loss), Unrealized $ 202,000us-gaap_ForeignCurrencyTransactionGainLossUnrealized $ 32,000us-gaap_ForeignCurrencyTransactionGainLossUnrealized
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 88,097us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount 2,234,994us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Furniture and Fixtures [Member] | Maximum [Member]    
Accounting Policies [Abstract]    
Property, Plant and Equipment, Useful Life 7 years  
Furniture and Fixtures [Member] | Minimum [Member]    
Accounting Policies [Abstract]    
Property, Plant and Equipment, Useful Life 5 years  
Office Equipment [Member] | Maximum [Member]    
Accounting Policies [Abstract]    
Property, Plant and Equipment, Useful Life 5 years  
Office Equipment [Member] | Minimum [Member]    
Accounting Policies [Abstract]    
Property, Plant and Equipment, Useful Life 3 years  
Long-Term Incentive Plan, Payment Commencing in February 2021 and Ending in December 2023 [Member]    
Accounting Policies [Abstract]    
Deferred Compensation, Reward Payable, Equal Consecutive Monthly Installments 35nhtc_DeferredCompensationRewardPayableEqualConsecutiveMonthlyInstallments
/ us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis
= nhtc_LongTermIncentivePlanPaymentCommencingInFebruary2021AndEndingInDecember2023Member
 
Deferred Compensation, Reward Payable, Percentage 50.00%nhtc_DeferredCompensationRewardPaymentPercentage
/ us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis
= nhtc_LongTermIncentivePlanPaymentCommencingInFebruary2021AndEndingInDecember2023Member
 
Long-Term Incentive Plan, Payment Commencing in February of the Calendar Year Immediately Following the Conclusion of the Performance Period [Member]    
Accounting Policies [Abstract]    
Deferred Compensation, Reward Payable, Equal Consecutive Monthly Installments 35nhtc_DeferredCompensationRewardPayableEqualConsecutiveMonthlyInstallments
/ us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis
= nhtc_LongTermIncentivePlanPaymentCommencingInFebruaryOfTheCalendarYearImmediatelyFollowingTheConclusionOfThePerformancePeriodMember
 
Deferred Compensation, Reward Payable, Percentage 50.00%nhtc_DeferredCompensationRewardPaymentPercentage
/ us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis
= nhtc_LongTermIncentivePlanPaymentCommencingInFebruaryOfTheCalendarYearImmediatelyFollowingTheConclusionOfThePerformancePeriodMember