Document And Entity Information
Note To Financial Statement Details Textual
statementnote4netincomepersharetables
statementnote5marketablesecuritiestables
statementnote6inventoriestables
Excess tax deficiencies
statementnote4netincomepersharecomponentsofcommonsharesoutstandingdetails
statementnote5marketablesecuritiesfairvalueofmarketablesecuritiesbymaturitydetails
statementnote5marketablesecuritiesreconciliationofmarketablesecuritiesdetails
Expenses
statementnote5marketablesecuritiessecuritiesinacontinuouslosspositiondetails
Total
Fair Market Value
statementnote6inventoriessummaryofinventoriesdetails
Notes To Financial Statements
Notes To Financial Statements [Abstract]
us-gaap_Revenues
Total revenue
us-gaap_AvailableForSaleSecurities
Available-for-sale Securities
us-gaap_PaymentsOfDividendsCommonStock
Payment of dividends to shareholders
Marketable securities, long-term
Fair Value, Inputs, Level 2 [Member]
Fair Value, Inputs, Level 1 [Member]
Fair Value, Inputs, Level 3 [Member]
Fair Value Hierarchy [Domain]
Marketable securities, short-term
Fair Value, Hierarchy [Axis]
Cash dividends declared per common share (in dollars per share)
Common Stock, Dividends, Per Share, Declared
INVESTING ACTIVITIES
Proceeds from sale of common stock
Equity Component [Domain]
Equity Components [Axis]
us-gaap_IncreaseDecreaseInDeferredRevenue
Deferred revenue
Accounts payable and accrued expenses
Quarterly Financial Information [Text Block]
Adjusted Cost
Common stock, shares outstanding (in shares)
Gross Unrealized Gains
us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Gross Unrealized Losses
Diluted (in shares)
Shares used in computing net income per share – diluted (in shares)
us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
nvec_NumberOfOtherThanTemporarilyImpairedMarketableSecurities
Number of Other-than-temporarily Impaired Marketable Securities
Represents the number of marketable securities the company considers other-than-temporarily impaired.
Subsequent Event [Member]
Net income per share – diluted (in dollars per share)
Subsequent Event Type [Domain]
Subsequent Event Type [Axis]
Cash and cash equivalents
Cash and cash equivalents at beginning of period
Cash and cash equivalents at end of period
Subsequent Events [Text Block]
Weighted average common shares outstanding – basic (in shares)
Basic (in shares)
us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
Gross unrealized losses, greater than 12 months
Contract research and development
Net income per share – basic (in dollars per share)
Scenario, Unspecified [Domain]
Scenario [Axis]
us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions
us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsGreaterThanOrEqualToOneYear
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year
us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses
Total gross unrealized losses
us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
Gross unrealized losses, less than 12 months
Corporate Bond Securities [Member]
Fair market value, greater than 12 months
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value
Fair market value, less than 12 months
Total fair market value
us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit
us-gaap_OpenTaxYear
Open Tax Year
us-gaap_UnrecognizedTaxBenefits
Unrecognized Tax Benefits
Accounting Policies [Abstract]
us-gaap_StockRepurchasedAndRetiredDuringPeriodValue
Stock Repurchased and Retired During Period, Value
Less than 1 year
Statement of Financial Position [Abstract]
Relationship to Entity [Domain]
Title of Individual [Axis]
us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets
Prepaid expenses and other assets
us-gaap_LiabilitiesFairValueDisclosure
Financial and Nonfinancial Liabilities, Fair Value Disclosure
us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued
Unrecognized Tax Benefits, Interest on Income Taxes Accrued
Statement of Cash Flows [Abstract]
Latest Tax Year [Member]
Earliest Tax Year [Member]
Stock Repurchase Plan Disclosure [Text Block]
The entire disclosure for the stock repurchase plan.
us-gaap_AllocatedShareBasedCompensationExpense
Allocated Share-based Compensation Expense
Tax Period [Domain]
1-3 years
Fair value of available-for-sale debt securities maturing in one to three years.
Tax Period [Axis]
3-5 years
Fair value of available-for-sale debt securities maturing in three through five years.
us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest
Comprehensive income
Schedule of Unrealized Loss on Investments [Table Text Block]
us-gaap_IncreaseDecreaseInAccountsReceivable
Accounts receivable
Schedule of Available-for-sale Securities Reconciliation [Table Text Block]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
Income before taxes
us-gaap_LiabilitiesAndStockholdersEquity
Total liabilities and shareholders’ equity
Provision for income taxes
Retained earnings
Accumulated other comprehensive income (loss)
Product sales
us-gaap_PolicyTextBlockAbstract
Accounting Policies
us-gaap_IncreaseDecreaseInInventories
Inventories
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]
Marketable Securities [Table Text Block]
Statement [Table]
Income Statement [Abstract]
FINANCING ACTIVITIES
Class of Stock [Axis]
Schedule of Weighted Average Number of Shares [Table Text Block]
Prepaid expenses and other assets
us-gaap_DisclosureTextBlockAbstract
Notes to Financial Statements
us-gaap_LiabilitiesCurrent
Total current liabilities
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]
Raw materials
Revenue
Finished goods
Work in process
us-gaap_OperatingExpenses
Total expenses
Changes in operating assets and liabilities:
Long-term deferred tax assets
Interest income
Non-employee Director Stock Options [Member]
An arrangement whereby a non-employee director is issued automatic stock options on their election or reelection to the company's Board.
us-gaap_OperatingIncomeLoss
Income from operations
Deferred revenue
Schedule of Inventory, Current [Table Text Block]
Cost of sales
Inventory Disclosure [Text Block]
nvec_StockRepurchaseProgramAuthorizedAdditionalAmount
Stock Repurchase Program Authorized Additional Amount
Amount of additional stock repurchase plan authorized.
Deferred income taxes
us-gaap_GrossProfit
Gross profit
Amendment Flag
Common stock, $0.01 par value, 6,000,000 shares authorized; 4,841,010 issued and outstanding as of September 30, 2017 and March 31, 2017
us-gaap_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities
Excess tax deficiencies
Proceeds from maturities and sales of marketable securities
Common stock, shares authorized (in shares)
Common stock, shares issued (in shares)
Common stock, par value (in dollars per share)
Income Tax Disclosure [Text Block]
Stock-based compensation
Current Fiscal Year End Date
Document Fiscal Period Focus
Document Fiscal Year Focus
Document Period End Date
Document Type
us-gaap_DepreciationDepletionAndAmortization
Depreciation and amortization
Accounts payable
Document Information [Line Items]
Document Information [Table]
Accrued payroll and other
us-gaap_AssetsCurrent
Total current assets
Entity Filer Category
Entity Current Reporting Status
Entity Voluntary Filers
Entity Well-known Seasoned Issuer
us-gaap_PaymentsToAcquireMarketableSecurities
Purchases of marketable securities
us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
Stock Repurchase Program, Remaining Authorized Repurchase Amount
us-gaap_StockRepurchaseProgramAuthorizedAmount1
Stock Repurchase Program, Authorized Amount
Adjustments to reconcile net income to net cash provided by operating activities:
Dilutive effect of stock options (in shares)
Entity Central Index Key
Entity Registrant Name
us-gaap_AssetsFairValueDisclosure
Assets, Fair Value Disclosure
Entity [Domain]
Weighted average shares outstanding
Legal Entity [Axis]
Entity Common Stock, Shares Outstanding (in shares)
Cash paid during the period for income taxes
LIABILITIES AND SHAREHOLDERS’ EQUITY
us-gaap_Assets
Total assets
Additional paid-in capital
Inventories
Total inventories
Shareholders’ equity
Trading Symbol
us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Purchases of fixed assets
Business Description and Basis of Presentation [Text Block]
Net income
Net income
us-gaap_StockholdersEquity
Total shareholders’ equity
Selling, general, and administrative
OPERATING ACTIVITIES
Antidilutive Securities, Name [Domain]
Employee Stock Option [Member]
Allowance for uncollectible accounts
Antidilutive Securities [Axis]
Accounts receivable, net of allowance for uncollectible accounts of $15,000
Statement [Line Items]
Research and development
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]
Statement of Comprehensive Income [Abstract]
Municipal Bonds [Member]
Supplemental disclosures of cash flow information:
Unrealized gain (loss) from marketable securities, net of tax
Investments [Domain]
Investment Type [Axis]
Fair Value Disclosures [Text Block]
us-gaap_PropertyPlantAndEquipmentNet
Net fixed assets
ASSETS
Less accumulated depreciation and amortization
us-gaap_PropertyPlantAndEquipmentGross
Leasehold improvements
us-gaap_NetCashProvidedByUsedInFinancingActivities
Net cash used in financing activities
Machinery and equipment
us-gaap_NetCashProvidedByUsedInInvestingActivities
Net cash (used in) provided by investing activities
us-gaap_NetCashProvidedByUsedInOperatingActivities
Net cash provided by operating activities
us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
Decrease in cash and cash equivalents
us-gaap_TableTextBlock
Notes Tables
Fixed assets
Earnings Per Share [Text Block]