Annual report pursuant to Section 13 and 15(d)

Note 1 - Basic and Diluted Income Per Share (Details)

v2.4.1.9
Note 1 - Basic and Diluted Income Per Share (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Basic EPS:    
Net income available to common stockholders $ 20,360us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 4,074us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
Less: undistributed earnings to participating securities (127)us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic (31)us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic
Net income allocated to common stockholders 20,360us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic 4,074us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
Net income allocated to common stockholders (in shares) 12,131us-gaap_WeightedAverageNumberOfSharesOutstandingBasic 11,154us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Net income allocated to common stockholders (in dollars per share) $ 1.67us-gaap_EarningsPerShareBasic $ 0.36us-gaap_EarningsPerShareBasic
Effect of dilutive securities:    
Warrants to purchase common stock (in shares) 421us-gaap_IncrementalCommonSharesAttributableToCallOptionsAndWarrants  
Plus: reallocation of undistributed earnings to participating securities 5nhtc_PlusreallocationOfUndistributedEarningsToParticipatingSecurities  
Diluted EPS:    
Net income allocated to common stockholders plus assumed conversions 20,238us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted 4,043us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted
Net income allocated to common stockholders plus assumed conversions (in shares) 12,600us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding 11,331us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Net income allocated to common stockholders plus assumed conversions (in dollars per share) $ 1.61us-gaap_EarningsPerShareDiluted $ 0.36us-gaap_EarningsPerShareDiluted
Distributed [Member]    
Basic EPS:    
Net income available to common stockholders 20,233us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
/ us-gaap_StatementScenarioAxis
= nhtc_DistributedMember
4,043us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
/ us-gaap_StatementScenarioAxis
= nhtc_DistributedMember
Net income allocated to common stockholders $ 20,233us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
/ us-gaap_StatementScenarioAxis
= nhtc_DistributedMember
$ 4,043us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
/ us-gaap_StatementScenarioAxis
= nhtc_DistributedMember
Net income allocated to common stockholders (in shares) 12,131us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
/ us-gaap_StatementScenarioAxis
= nhtc_DistributedMember
11,154us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
/ us-gaap_StatementScenarioAxis
= nhtc_DistributedMember
Net income allocated to common stockholders (in dollars per share) $ 1.67us-gaap_EarningsPerShareBasic
/ us-gaap_StatementScenarioAxis
= nhtc_DistributedMember
$ 0.36us-gaap_EarningsPerShareBasic
/ us-gaap_StatementScenarioAxis
= nhtc_DistributedMember
Restricted Stock [Member]    
Effect of dilutive securities:    
Non-vested restricted stock (in shares) 48us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
177us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember