Document And Entity Information
Note To Financial Statement Details Textual
statementsignificantaccountingpoliciespolicies
statementnoteabasisofpresentationandsummaryofsignificantaccountingpoliciestables
Segment Reporting [Abstract]
statementnotebinventoriestables
statementnotecpropertyandequipmenttables
statementnotedothercomprehensiveincomelosstables
statementnotefdefinedbenefitpensionplantables
Amendment Flag
statementnotegeconomicdependencytables
statementnotehsegmentinformationtables
statementnoteabasisofpresentationandsummaryofsignificantaccountingpoliciescalculationofbasicanddilutednetincomepercommonsharedetails
statementnotebinventoriessummaryofinventoriesnetdetails
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Class of Stock [Axis]
statementnotecpropertyandequipmentpropertyandequipmentdetails
statementnotedothercomprehensivelossothercomprehensivelossincomedetails
statementnotefemployeebenefitplanscomponentsincludedindefinedbenefitpensionplansnetperiodicbenefitexpensedetails
statementnotegeconomicdependencysubstantialnetsalestocertaincustomersdetails
statementnotehsegmentinformationoperatingresultsbybusinesssegmentdetails
statementnotegeconomicdependencysubstantialnetpurchasefromcertainsupplierdetails
statementnotehsegmentinformationnetsalesbygeographicregiondetails
Document Fiscal Year Focus
Total Assets
statementnotehsegmentinformationassetsbybusinesssegmentdetails
Document Fiscal Period Focus
Notes To Financial Statements
statementnotehsegmentinformationassetsandcapitalexpendituresbygeographicalregiondetails
Non-cash compensation
Notes To Financial Statements [Abstract]
Document Period End Date
Schedule of Segment Reporting Information, by Segment [Table Text Block]
Interest cost
Current Fiscal Year End Date
us-gaap_OtherComprehensiveIncomeLossNetOfTax
Other comprehensive income
us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets
Expected return on plan assets
Deferred rent
Income from Operations
Net Sales
us-gaap_AssetsCurrent
Total current assets
Hedging Relationship [Axis]
Entity Current Reporting Status
Hedging Relationship [Domain]
Entity Voluntary Filers
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
Income before income taxes
Cash Flow Hedging [Member]
Provision for income taxes
Entity Filer Category
Document Type
us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions
Tax Adjustments, Settlements, and Unusual Provisions
Statement of Cash Flows [Abstract]
Changes in operating assets and liabilities:
us-gaap_ForeignCurrencyContractAssetFairValueDisclosure
Foreign Currency Contract, Asset, Fair Value Disclosure
Income tax receivable
Entity Well-known Seasoned Issuer
Proceeds from sale of property & equipment
Long-Lived assets
Supplier Concentration Risk [Member]
Other noncurrent assets, net
Statement of Financial Position [Abstract]
us-gaap_LiabilitiesCurrent
Total current liabilities
Adjustments to reconcile net income to net cash used in operating activities:
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Domain]
Reclassification out of Accumulated Other Comprehensive Income [Axis]
Comprehensive Income (Loss) Note [Text Block]
Fair Value, Inputs, Level 2 [Member]
Fair Value, Inputs, Level 1 [Member]
Fair Value Hierarchy [Domain]
Fair Value, Hierarchy [Axis]
Fair Value, Inputs, Level 3 [Member]
Geographic Concentration Risk [Member]
Customer Concentration Risk [Member]
Concentration Risk Type [Axis]
us-gaap_OtherIncome
Other Income
Concentration Risk Type [Domain]
us-gaap_NumberOfReportableSegments
Number of Reportable Segments
Building and Building Improvements [Member]
Foreign exchange gain (loss)
Leasehold Improvements [Member]
Pension expense
Property, Plant and Equipment, Type [Axis]
Property, Plant and Equipment, Type [Domain]
us-gaap_LongtermDebtPercentageBearingVariableInterestAmount
Long-term Debt, Percentage Bearing Variable Interest, Amount
Land [Member]
us-gaap_GainLossOnCashFlowHedgeIneffectivenessNet
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net
Depreciation and amortization
Segment Reporting Disclosure [Text Block]
us-gaap_LiabilitiesAndStockholdersEquity
Total liabilities and stockholders’ equity
us-gaap_DebtInstrumentTerm
Debt Instrument, Term
us-gaap_CashFlowHedgeDerivativeInstrumentAssetsAtFairValue
Cash Flow Hedge Derivative Instrument Assets at Fair Value
Schedules of Concentration of Risk, by Risk Factor [Table Text Block]
Furniture and Fixtures [Member]
Concentration Risk Disclosure [Text Block]
Accumulated other comprehensive income (loss)
Retained earnings
Property, plant and equipment, depreciable life in years
Fixed assets in accounts payable
us-gaap_RatioOfIndebtednessToNetCapital1
Ratio of Indebtedness to Net Capital
invest_DerivativeNotionalAmount
Derivative, Notional Amount
Cash flows from operating activities
Basic net income per common share (in dollars per share)
Basic weighted average common shares outstanding (in shares)
us-gaap_ProceedsFromLicenseFeesReceived
Proceeds from License Fees Received
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
London Interbank Offered Rate (LIBOR) [Member]
us-gaap_GrossProfit
Gross profit
Statement [Line Items]
us-gaap_OperatingIncomeLoss
Income from operations
Income from operations
Variable Rate [Domain]
Variable Rate [Axis]
Revenue from External Customers by Geographic Areas [Table Text Block]
Long-lived Assets by Geographic Areas [Table Text Block]
us-gaap_PaymentsForRepurchaseOfCommonStock
Repurchase of common stock
Accumulated Defined Benefit Plans Adjustment [Member]
Interest income
Cash and cash equivalents
Cash and cash equivalents at beginning of period
Cash and cash equivalents at end of period
Derivative Contract [Domain]
Current assets:
Consolidation Items [Domain]
Consolidation Items [Axis]
Operating Segments [Member]
Corporate, Non-Segment [Member]
Interest
Disclosure of non-cash activities:
Taxes
us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
Net increase (decrease) in cash and cash equivalents
us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Debt Instrument, Basis Spread on Variable Rate
Other, net
us-gaap_DebtInstrumentInterestRateStatedPercentage
Debt Instrument, Interest Rate, Stated Percentage
us-gaap_NonoperatingIncomeExpense
us-gaap_TreasuryStockValueAcquiredCostMethod
Treasury Stock, Value, Acquired, Cost Method
us-gaap_TreasuryStockValue
Treasury stock, at cost, 594,787 shares at December 31, 2014 and 515,923 at June 30, 2014
Revenue Recognition, Policy [Policy Text Block]
us-gaap_NetCashProvidedByUsedInFinancingActivities
Net cash used by financing activities
us-gaap_RoyaltyExpense
Royalty Expense
naii_AdditionalLicenseFeesUponAchievementOfCertainMilestones
Additional License Fees Upon Achievement of Certain Milestones
Amount of license fees incurred upon the achievement of certain milestones per installment payment.
Legal Entity [Axis]
naii_AdditionalLicenseFeesReceivableUponAchievementOfCertainMilestones
Additional License Fees Receivable Upon Achievement of Certain Milestones
Aggregate amount of license fees incurred upon the achievement of certain milestones.
naii_NumberOfInstallmentPayments
Number of Installment Payments
The number of installment payments that must be made as apart of a transaction.
Entity Registrant Name
Raw materials
Entity Central Index Key
Entity [Domain]
naii_RoyaltyAndLicensingRevenue
Royalty and Licensing Revenue
Royalty and licensing revenue
Amendment [Member]
An agreement that has been amended from its original terms.
Capital Expenditures
Capital expenditures
Prior to Amendment [Member]
A scenario prior to an amendment.
Swiss Federal Tax Administration (FTA) [Member]
Installment [Member]
Installment [member]
2009 Omnibus Stock Incentive Plan [Member]
Omnibus stock incentive plan adopted in 2009.
Entity Common Stock, Shares Outstanding (in shares)
Equity Components [Axis]
us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
Line of Credit Facility, Current Borrowing Capacity
us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Line of Credit Facility, Maximum Borrowing Capacity
Accounts receivable, allowance for doubtful accounts
Accounts receivable - less allowance for doubtful accounts of $16 at December 31, 2014 and $94 at June 30, 2014
Equity Component [Domain]
Other comprehensive income before reclassifications
us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax
Amounts reclassified from OCI
Employee Stock Option [Member]
us-gaap_LineOfCreditFacilityCommitmentFeeAmount
Line of Credit Facility, Commitment Fee Amount
us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
us-gaap_TreasuryStockSharesAcquired
Treasury Stock, Shares, Acquired
Change in unrealized gain resulting from change in fair value of derivative instruments, net of tax
The change during the period in an unrealized gain (loss) on derivatives.
Subsequent Event Type [Domain]
Subsequent Event [Member]
Debt Instrument [Axis]
Debt Instrument, Name [Domain]
Subsequent Event Type [Axis]
Diluted (in shares)
Diluted weighted average common shares outstanding (in shares)
us-gaap_InventoryValuationReserves
Reserves
us-gaap_OpenTaxYear
Open Tax Year
Inventories, net
Income Tax Authority, Name [Axis]
Work in progress
State and Local Jurisdiction [Member]
Income Tax Authority, Name [Domain]
Other noncurrent liabilities, net
Finished goods
Common stock, outstanding (in shares)
New Accounting Pronouncements, Policy [Policy Text Block]
Income Tax Authority [Domain]
Diluted net income per common share (in dollars per share)
Income Tax Authority [Axis]
Preferred stock, shares outstanding (in shares)
Foreign Tax Authority [Member]
Domestic Tax Authority [Member]
naii_MinimumPrepaymentAmountUnderLineOfCredit
Minimum Prepayment Amount Under Line of Credit
The minimum payment amount that may be prepaid on a line of credit facility with a fixed interest rate.
naii_LineOfCreditFacilityMaximumBorrowingCapacityAnnualReduction
Line of Credit Facility Maximum Borrowing Capacity Annual Reduction
Amount of annual reduction on a line of credit facility.
UNITED STATES
naii_LineOfCreditFacilityOutstandingDailyBalanceDuringPeriod
Line of Credit Facility Outstanding Daily Balance During Period
The amount that a balance for a line of credit must be maintained at for a predetermined amount of days as part of the agreement.
Machinery and Equipment [Member]
naii_LineOfCreditCovenantNumberOfConsecutiveDaysThatOutstandingBalanceMustBeZero
Line of Credit Covenant Number of Consecutive Days That Outstanding Balance Must Be Zero
The number of consecutive days that the outstanding balance must be zero on a line of credit as part of the agreement.
naii_DebtPrePaymentPenalty
Debt Pre Payment Penalty
Amount of penalties associated with the prepayment of debt.
naii_LineOfCreditFacilityMaximumAmountOutstandingAfterReduction
Line of Credit Facility Maximum Amount Outstanding after Reduction
Maximum amount outstanding after an annual reduction on a line of credit facility.
Balance Sheet Location [Domain]
naii_DebtPrepaymentPenaltyRate
Debt Prepayment Penalty Rate
Percentage of penalties associated with the prepayment of debt.
Derivative Instrument [Axis]
Balance Sheet Location [Axis]
Income Tax Disclosure [Abstract]
naii_DebtInstrumentBasisSpreadOnElectedFixedRateBorrowing
Debt Instrument Basis Spread on Elected Fixed Rate Borrowing
The percentage points added to the reference rate to compute fixed rate elections on the debt instrument.
naii_NetIncomeRequiredInFutureForIncomeCovenant
Net Income Required in Future for Income Covenant
Amount of net income after taxes that must be maintained by the borrower in a line of credit facility.
Tax Period [Domain]
us-gaap_InterestExpense
Interest expense
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]
us-gaap_ComprehensiveIncomeNetOfTax
Comprehensive income
Tax Period [Axis]
Vehicles [Member]
Earliest Tax Year [Member]
Equity [Abstract]
us-gaap_StockRepurchaseProgramAuthorizedAmount1
Stock Repurchase Program, Authorized Amount
us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
Net periodic expense
Cost of Goods, Total [Member]
Other income:
us-gaap_IncreaseDecreaseInOtherOperatingAssets
Other assets
us-gaap_GainLossOnDispositionOfAssets
Loss (gain) on disposal of assets
Customer 1 [Member]
Customer 1 in a set of customers.
Customer 2 [Member]
Customer 2 in a set of customers.
Customer 3 [Member]
Customer 3 in a set of customers.
us-gaap_TreasuryStockAcquiredAverageCostPerShare
Treasury Stock Acquired, Average Cost Per Share
Selling, general and administrative expenses
Natural Alternatives International Europe SA [Member]
The entity Natural alternatives international Europe SA.
Increase (decrease) in provision for uncollectible accounts receivable
us-gaap_IncreaseDecreaseInIncomeTaxes
Income taxes
Property and equipment
us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
Less: accumulated depreciation and amortization
Amended Line of Credit Facility [Member]
A line of credit facility that has been amended from its original terms.
Prepaid Expenses and Other Current Assets [Member]
Property and equipment, net
Fixed Loans [Member]
Fixed loans [member]
us-gaap_EffectiveIncomeTaxRateContinuingOperations
Effective Income Tax Rate Reconciliation, Percent
naii_NumberOfYearsCompensationUsedForBenefitObligationAssumptions
Number of Years Compensation Used for Benefit Obligation Assumptions
The period of employment before retirement that is used to determine what amount of compensation to use as a a baseline for the companies defined benefit plan.
Commitments and Contingencies Disclosure [Abstract]
% of total net sales
Concentration Risk, Percentage
Credit Facility [Domain]
Supplier 1 [Member]
Supplier 1 in a set of suppliers.
Plan Name [Axis]
Plan Name [Domain]
Geographical [Domain]
Geographical [Axis]
United States [Member]
United states [member]
Patentand Trademark Licensing [Member]
Business segment related to patentand trademark licensing.
Branded Products [Member]
Business segment related to branded products.
Markets Outside the United States [Member]
Markets located outside of the United States.
Private Label Contract Manufacturing [Member]
Business segment related to private label contract manufacturing.
Award Type [Axis]
us-gaap_Revenues
Revenues
Sales Revenue, Net [Member]
us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax
Concentration Risk Benchmark [Axis]
Concentration Risk Benchmark [Domain]
Pension and Other Postretirement Benefits Disclosure [Text Block]
Compensation and Retirement Disclosure [Abstract]
Other Noncurrent Assets Net [Member]
Non current assets not otherwise defined.
Unrealized gain (loss) resulting from change in fair value of derivative instruments, net of tax
Cash Flow Hedging Foreign Exchange Contract [Member]
A foreign currency derivative designated as cash flow hedging instruments.
Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block]
us-gaap_NetCashProvidedByUsedInOperatingActivities
Net cash provided by operating activities
Cash flows from investing activities
Europe [Member]
Net income per common share:
Minimum [Member]
Maximum [Member]
Range [Domain]
us-gaap_PolicyTextBlockAbstract
Accounting Policies
Income Statement Location [Domain]
Income Statement Location [Axis]
us-gaap_TableTextBlock
Notes Tables
Range [Axis]
Customer [Domain]
Customer [Axis]
us-gaap_LineOfCredit
Long-term Line of Credit
Antidilutive Securities [Axis]
us-gaap_OtherComprehensiveIncomeLossTax
Tax effect of OCI activity
Debt Disclosure [Abstract]
Antidilutive Securities, Name [Domain]
Equity Award [Domain]
Other Comprehensive Income (Loss), Net of Tax [Abstract]
us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent
Debt Disclosure [Text Block]
Equity Option [Member]
Restricted Stock [Member]
Inventory Disclosure [Text Block]
us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities
Accrued compensation and employee benefits
Cash paid during the period for:
Schedule of Inventory, Current [Table Text Block]
% of total raw material purchases
Percentage of raw materials purchased from supplier
Raw Material Purchases by Supplier
Raw material purchases by supplier
us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities
Accounts payable and accrued liabilities
Common stock, shares authorized (in shares)
Deferred income taxes
Common stock, issued (in shares)
Common stock, par value (in dollars per share)
us-gaap_DeferredTaxAssetsNetNoncurrent
Deferred income taxes
Treasury Stock [Text Block]
Net income
Net income
Numerator
Legal Matters and Contingencies [Text Block]
us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount
Treasury stock, shares (in shares)
Prepaids and other current assets
us-gaap_IncreaseDecreaseInInventories
Inventories, net
Common stock; $.01 par value; 20,000,000 shares authorized; issued and outstanding (net of treasury shares) 6,918,890 at December 31, 2014 and 6,997,754 at June 30, 2014
Accrued compensation and employee benefits
Earnings Per Share, Policy [Policy Text Block]
Income taxes payable
Share-based Goods and Nonemployee Services Transaction, Supplier [Domain]
Supplier [Axis]
Income Statement [Abstract]
us-gaap_ForeignCurrencyContractsLiabilityFairValueDisclosure
Foreign Currency Contracts, Liability, Fair Value Disclosure
Accounts payable
Fair Value Measurement, Policy [Policy Text Block]
Accrued liabilities
Credit Facility [Axis]
Preferred stock; $.01 par value; 500,000 shares authorized; none issued or outstanding
Weighted average common shares outstanding:
Denominator
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period
Preferred stock, shares issued (in shares)
Segments [Domain]
Preferred stock, shares authorized (in shares)
Total Assets [Member]
Represents total assets.
Cash flows from financing activities
Segments [Axis]
Statement [Table]
us-gaap_NetCashProvidedByUsedInInvestingActivities
Net cash used by investing activities
us-gaap_AllocatedShareBasedCompensationExpense
Allocated Share-based Compensation Expense
Customer 4 [Member]
Customer 4 [member
Scenario, Unspecified [Domain]
Income Tax Disclosure [Text Block]
Preferred stock par value (in dollars per share)
Scenario [Axis]
Net Sales and Income From Operations [Member]
Represents net sales and income from operations.
Dilutive effect of stock options (in shares)
Supplier 1 and 2 [Member]
Supplier 1 and 2 [member
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]
us-gaap_StockholdersEquity
Total stockholders’ equity
Property, Plant and Equipment [Table Text Block]
Additional paid-in capital
Basis of Accounting, Policy [Policy Text Block]
Property, Plant and Equipment Disclosure [Text Block]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate
Accounting Policies [Abstract]
us-gaap_FairValueNetAssetLiability
Fair Value, Net Asset (Liability)
naii_StockRepurchaseProgramAmountOfAdditionalSharesAuthorizedToBeRepurchased
Stock Repurchase Program, Amount of Additional Shares Authorized to be Repurchased
Amount of additional shares authorized for repurchase under the stock repurchase plan .
Organization, Consolidation and Presentation of Financial Statements [Abstract]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period
us-gaap_DerivativeInstrumentsLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion
us-gaap_Liabilities
Total liabilities
us-gaap_DerivativeInstrumentsGainReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period
Net sales
Revenue, Net
Cost of goods sold
us-gaap_DerivativeInstrumentsLossRecognizedInOtherComprehensiveIncomeEffectivePortion
Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion
us-gaap_DerivativeInstrumentsGainRecognizedInOtherComprehensiveIncomeEffectivePortion
Derivative Instruments, Gain Recognized in Other Comprehensive Income (Loss), Effective Portion
Commitments and contingencies
Schedule of Net Benefit Costs [Table Text Block]
Stockholders’ equity:
naii_NumberOfPatentsInLawsuit
Number of Patents In Lawsuit
The number of patents being disputed in a lawsuit.
Current liabilities:
us-gaap_IncreaseDecreaseInAccountsReceivable
Accounts receivable
Assets
Total assets
Assets
Accrued Liabilities [Member]
Primary financial statement caption encompassing accrued liabilities.
us-gaap_DisclosureTextBlockAbstract
Notes to Financial Statements
Derivative Instruments and Hedging Activities Disclosure [Text Block]
Supplier 2 [Member]
Supplier 2 in a set of suppliers.
Derivative Instruments and Hedging Activities Disclosure [Abstract]