Document And Entity Information Note To Financial Statement Details Textual statementnote2acquisitiontables statementnote4inventoriestables London Interbank Offered Rate (LIBOR) [Member] us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities Excess Tax Benefit from Share-based Compensation, Financing Activities statementnote5propertyequipmentandimprovementstables statementnote6goodwillintangibleassetsandlongtermassetstables Type of Adoption [Domain] statementnote7revolvingcreditagreementtables Adjustments for New Accounting Pronouncements [Axis] statementnote8shareholdersequitytables Variable Rate [Domain] statementnote9incometaxestables Operating expenses: Variable Rate [Axis] statementnote11commitmentsandcontingenciestables statementnote12businesssegmentinformationtables statementnote2acquisitionscheduleofrecognizedidentifiedassetsacquiredandliabilitiesassumeddetails statementnote2acquisitionunauditedproformainformationdetails statementnote4inventoriescompositionofinventoriesdetails Revenues Revenues statementnote5propertyequipmentandimprovementsmajorclassesofpropertyequipmentandimprovementsdetails statementnote6goodwillintangibleassetsandlongtermassetsgoodwillactivitybysegmentdetails statementnote6goodwillintangibleassetsandlongtermassetscompositionofintangibleassetsdetails statementnote6goodwillintangibleassetsandlongtermassetsamortizationexpenseforintangibleassetsdetails statementnote7revolvingcreditagreementinterestratemarginsdetails statementnote8shareholdersequitynoncashstockcompensationexpensedetails statementnote8shareholdersequitystockoptionactivitydetails statementnote8shareholdersequitystockoptionassumptionsdetails statementnote9incometaxesincometaxexpensedetails statementnote9incometaxeseffectiveconsolidatedtaxratedetails statementnote11commitmentsandcontingencieschangesinproducewarrantyliabilitydetails statementnote12businesssegmentinformationsegmentactivitydetails Notes To Financial Statements Notes To Financial Statements [Abstract] us-gaap_PaymentsForRepurchaseOfCommonStock Cash paid to repurchase treasury stock us-gaap_LineOfCredit Long-term Line of Credit Proceeds from stock option exercise Proceeds from Stock Options Exercised INVESTING ACTIVITIES: Equity Component [Domain] Report Date [Axis] Equity Components [Axis] Financial Statement Filing Date [Domain] us-gaap_ComprehensiveIncomeNetOfTax Comprehensive income attributable to Ultralife Corporation Customer Contracts and Relationships [Member] Entity's established relationships with its customers through contracts and otherwise. us-gaap_TreasuryStockSharesAcquired Treasury Stock, Shares, Acquired Shareholders' Equity and Share-based Payments [Text Block] Applicable basis points for unused fee Line of Credit Facility, Unused Capacity, Commitment Fee Percentage us-gaap_PriorPeriodReclassificationAdjustment Prior Period Reclassification Adjustment Common stock, shares outstanding (in shares) us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity Line of Credit Facility, Maximum Borrowing Capacity Debt and Capital Leases Disclosures [Text Block] Payments of debt borrowings Weighted average shares outstanding - diluted (in shares) us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet Total Consideration Potential common shares (in shares) President [Member] us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilities Non-Current Liabilities Mergers, Acquisitions and Dispositions Disclosures [Text Block] Line of Credit Facility, Lender [Domain] us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent Deferred Income Taxes Net income per share attributable to Ultralife common shareholders – diluted (in dollars per share) Lender Name [Axis] Computer Equipment [Member] us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesCurrent Income Taxes Payable Cash Cash, Beginning of period Cash, End of period us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable Accounts Payable Machinery and Equipment [Member] Weighted average shares outstanding – basic (in shares) KeyBank [Member] Related to the lender KeyBank. Leverage Ratio Less Than 1.5 [Member] Related to debt instruments when the company's leverage ratio is less than 1.5. Net income per share attributable to Ultralife common shareholders – basic (in dollars per share) ulbi_MinimumTangibleNetWorth Minimum Tangible Net Worth The minimum tangible net worth of the company required for certain debt covenants. Property, Plant & Equipment Scenario, Unspecified [Domain] Selling, General and Administrative Expenses [Member] Leverage Ratio Between 1.5 and 2.5 [Member] Related to debt instruments where the company's leverage ratio is between 1.5 and 2.5. Scenario, Forecast [Member] Leverage Ratio Greater than 2.5 [Member] Related to debt instruments where the leverage ratio is greater than 2.5. Identifiable Intangible Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill us-gaap_LongTermPurchaseCommitmentAmount Long-term Purchase Commitment, Amount Scenario [Axis] Internal Revenue Service (IRS) [Member] Income Tax Authority, Name [Domain] Foreign Tax Authority [Member] Accounts Receivable Domestic Tax Authority [Member] Prepaids and Other Current Assets Income Tax Authority, Name [Axis] State and Local Jurisdiction [Member] Inventory us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents Cash Income Tax Authority [Domain] Long-term Purchase Commitment, Category of Item Purchased [Domain] Income Tax Authority [Axis] Category of Item Purchased [Axis] us-gaap_TreasuryStockCarryingBasis Treasury stock - at cost; 4,015,752 shares us-gaap_BusinessCombinationConsiderationTransferred1 Business Combination, Consideration Transferred Income Statement Location [Domain] us-gaap_TreasuryStockValueAcquiredCostMethod Treasury Stock, Value, Acquired, Cost Method Income Statement Location [Axis] Research and Development Expense [Member] Maximum [Member] Range [Domain] us-gaap_OpenTaxYear Open Tax Year Other (expense) income: us-gaap_NetIncomeLossAttributableToNoncontrollingInterest Non-Controlling Interest Net loss (income) attributable to non-controlling interest Minimum [Member] Accounts payable and other liabilities Range [Axis] Accounting Policies [Abstract] Relationship to Entity [Domain] Statement of Financial Position [Abstract] Title of Individual [Axis] us-gaap_IncreaseDecreaseInDeferredIncomeTaxes Deferred income tax benefit Stockholders' Equity Note Disclosure [Text Block] us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic Basic (in dollars per share) us-gaap_IncreaseDecreaseInPrepaidExpense Prepaid expenses and other assets us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted Diluted (in dollars per share) Statement of Cash Flows [Abstract] Latest Tax Year [Member] ulbi_SharebasedCompensationArrangementBySharebasedPaymentAwardPlanModificationNumberOfShares Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Number of Shares Number of shares affected by the modification of an equity-based compensation plan. Earliest Tax Year [Member] us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss Net income attributable to Ultralife us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual Business Acquisition, Pro Forma Information [Table Text Block] us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax Operating income Stock-based comepensation expense us-gaap_BusinessAcquisitionsProFormaRevenue Revenue Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Tax Period [Domain] us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised Exercised (in shares) Tax Period [Axis] us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross Stock Issued During Period, Shares, Restricted Stock Award, Gross Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Net income Net income us-gaap_IncreaseDecreaseInAccountsReceivable Accounts receivable us-gaap_TaxCreditCarryforwardAmount Tax Credit Carryforward, Amount Finite-lived Intangible Assets Amortization Expense [Table Text Block] Granted (in shares) Other non-current liabilities Proceeds from debt borrowing us-gaap_OperatingLossCarryforwards Operating Loss Carryforwards Trade Names [Member] us-gaap_DeferredTaxAssetsValuationAllowance Deferred Tax Assets, Valuation Allowance Income Before Income Taxes Deferred income taxes us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and shareholders' equity Income tax provision Income Tax Expense (Benefit) Tax Provision Total Trademarks [Member] Effective Income Tax Rate Accumulated deficit Corporate Segment [Member] Accumulated other comprehensive loss Segments [Axis] Segments [Domain] us-gaap_PolicyTextBlockAbstract Accounting Policies us-gaap_IncreaseDecreaseInInventories Inventories Deferred income taxes ulbi_MinimumFixedChargeCoverageRatio Minimum Fixed Charge Coverage Ratio The minimum fixed charge coverage ratio required for certain debt covenants. Credit Facility [Domain] us-gaap_DeferredTaxAssetsGross Deferred Tax Assets, Gross Statement [Table] Revolving Credit Facility [Member] Credit Facility [Axis] FINANCING ACTIVITIES: Income Statement [Abstract] Schedule of Segment Reporting Information, by Segment [Table Text Block] Interest Rate Margins on Outstanding Debt [Table Text Block] Tabular disclosure of interest rate margins on outstanding debt. Intellectual Property [Member] 2014 Long-term Incentive Plan [Member] Represents the long-term incentive stockholder's equity compensation plan. us-gaap_NumberOfOperatingSegments Number of Operating Segments Class of Stock [Axis] Award Type [Axis] Equity Award [Domain] Customer Relationships [Member] Finite-Lived Intangible Assets, Major Class Name [Domain] Segment Reporting Disclosure [Text Block] Finite-Lived Intangible Assets by Major Class [Axis] us-gaap_LossContingencyDamagesSoughtValue Loss Contingency, Damages Sought, Value Prepaid expenses and other current assets us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements us-gaap_LiabilitiesCurrent Total current liabilities us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired Acquisition of Accutronics, net of cash acquired New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Raw materials us-gaap_InterestAndDebtExpense Interest and financing expense Accrued expenses and other current liabilities us-gaap_PaymentsToAcquireBusinessesGross Payments to Acquire Businesses, Gross Reclassification of Current Deferred Tax Assets to Noncurrent [Member] Related to a reclassification of current deferred tax asset amounts to noncurrent deferred tax assets during the period due to the adoption of a new accounting pronouncement. Finished goods Changes in operating assets and liabilities: Miscellaneous ulbi_CurrentPeriodReclassificationAdjustment Current Period Reclassification Adjustment The amount of a reclassification adjustment made to current period financial statement amounts. Exercisable - weighted average exercise price (in dollars per share) Work in process us-gaap_OperatingExpenses Total operating expenses Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Share-based Compensation, Stock Options, Activity [Table Text Block] Base Rate [Member] December 31, 2016 [Member] Represents the reporting date of December 31, 2016. Measurement period adjustment Property, Plant and Equipment [Table Text Block] Effect of foreign currency translation Property, Plant and Equipment Disclosure [Text Block] Dividends Risk-Free Interest Rate Acquisition of Accutronics Volatility Factor Segment Contribution us-gaap_OperatingIncomeLoss Operating income Schedule of Inventory, Current [Table Text Block] Cost of products sold Inventory Disclosure [Text Block] us-gaap_DeferredIncomeTaxExpenseBenefit Deferred Income Tax Provision Weighted Average Expected Life (Years) (Year) us-gaap_GrossProfit Gross profit Treasury stock, shares (in shares) Amendment Flag Common stock – par value $.10 per share; authorized 40,000,000 shares; issued – 19,567,642 shares at July 2, 2017 and 19,324,723 shares at December 31, 2016; outstanding – 15,551,890 shares at July 2, 2017 and 15,308,971 at December 31, 2016 Accruals for warranties issued Commitments and Contingencies Disclosure [Text Block] us-gaap_ProductWarrantyAccrualPayments Settlements made Common stock, shares authorized (in shares) Common stock, shares issued (in shares) Security deposits and other non-current assets Income Tax Disclosure [Text Block] Common stock, par value (in dollars per share) Letter of Credit [Member] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Stock-based compensation Current Fiscal Year End Date Capital Addition Purchase Commitments [Member] Options vested and expected to vest - weighted average exercise price (in dollars per share) Options vested and expected to vest - weighted average remaining contractual term (Year) Exercisable - aggregate intrinsic value Vested and Expected to Vest (in shares) Document Fiscal Period Focus Document Fiscal Year Focus Options vested and expected to vest - aggregate intrinsic value Exercisable - weighted average remaining contractual term (Year) Document Period End Date Preferred stock – par value $.10 per share; authorized 1,000,000 shares; none issued Preferred stock, shares issued (in shares) Document Type us-gaap_BusinessCombinationAcquisitionRelatedCosts Business Combination, Acquisition Related Costs Options exercisable (in shares) Options outstanding - aggregate intrinsic value Options outstanding - weighted average remaining contractual term (Year) Preferred stock, shares authorized (in shares) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Schedule of Product Warranty Liability [Table Text Block] Accounts payable Document Information [Line Items] Document Information [Table] Preferred stock, par value (in dollars per share) Accrued compensation and related benefits Depreciation expense us-gaap_AssetsCurrent Total current assets us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Entity Filer Category Entity Current Reporting Status Schedule of Finite-Lived Intangible Assets [Table Text Block] Entity Voluntary Filers Entity Well-known Seasoned Issuer us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice Options outstanding - weighted average exercise price (in dollars per share) Options outstanding - weighted average exercise price (in dollars per share) Forfeited or expired - weighted average exercise price (in dollars per share) Granted - weighted average exercise price (in dollars per share) us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased Stock Repurchase Program, Number of Shares Authorized to be Repurchased Exercised - weighted average exercise price (in dollars per share) Amortization of intangible assets Adjustments to reconcile net income to net cash provided by (used in) operating activities: us-gaap_CurrentStateAndLocalTaxExpenseBenefit State us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements us-gaap_CashPeriodIncreaseDecrease INCREASE (DECREASE) IN CASH Entity Central Index Key Entity Registrant Name Effect of exchange rate changes on cash us-gaap_CurrentForeignTaxExpenseBenefit Foreign Entity [Domain] Legal Entity [Axis] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber Options outstanding (in shares) Options outstanding (in shares) us-gaap_CurrentFederalTaxExpenseBenefit Federal us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod Forfeited or Expired (in shares) Non-controlling interest Current liabilities: Schedule of Goodwill [Table Text Block] Entity Common Stock, Shares Outstanding (in shares) Capital in excess of par value Goodwill and Intangible Assets Disclosure [Text Block] Total Assets us-gaap_Assets Total assets Inventories, net Total us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCost Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost Shareholders' equity: Trading Symbol us-gaap_InventoryAdjustments Inventory Adjustments us-gaap_PaymentsToAcquirePropertyPlantAndEquipment Cash paid for property, equipment and improvements us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1 Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Business Description and Basis of Presentation [Text Block] Net Income Attributable to Ultralife us-gaap_NetIncomeLoss Net income attributable to Ultralife Corporation us-gaap_StockholdersEquity Total Ultralife Corporation equity Plan Name [Axis] Selling, general and administrative Plan Name [Domain] Commitments and contingencies (Note 11) us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options us-gaap_Liabilities Total liabilities Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1 Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options Restricted Stock [Member] Intangible assets, net Net Restricted cash OPERATING ACTIVITIES: Employee Stock Option [Member] Accumulated Amortization Cost Trade accounts receivable, allowance for doubtful account Trade accounts receivable, net of allowance for doubtful accounts of $273 and $277, respectively Statement [Line Items] Research and development Accutronics Limited [Member] Represents information pertaining to acquisition of Accutronics Limited. Income taxes payable ulbi_PaymentsToAcquireBusinessesNetOfCashAcquiredWorkingCapitalAdjustment Payments to Acquire Businesses, Net of Cash Acquired Working Capital Adjustment The payments to acquire businesses based on the difference between actual and estimated amounts of working capital. Amortization of financing fees Goodwill Balance Balance ulbi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredIncomeTaxesOnIntangibleAssets Deferred Income Taxes on Intangible Assets Amount of deferred tax liability on intangible assets attributable to taxable temporary difference assumed at the acquisition date that are classified as current. ulbi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedLiabilitiesCurrent Accrued Expenses Amount of liabilities accrued, assumed at the acquisition date. Property, equipment and improvements, net Property, equipment and improvements, net Current assets: Construction in Progress [Member] us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment Less: Accumulated depreciation Property, Plant, and Equipment, Gross Accounting Standards Update 2016-09 [Member] Debt Instrument [Axis] Furniture and Fixtures [Member] Debt Instrument, Name [Domain] Communications Systems Segment [Member] Represents the company's communications systems segment. Battery & Energy Products Segment [Member] Represents the company's battery & energy products segment. us-gaap_ProductWarrantyAccrual Accrued warranty obligations – Beginning Accrued warranty obligations – Ending Interest rate margin on outstanding borrowings Debt Instrument, Basis Spread on Variable Rate Distributor Relationships [Member] Represents information pertaining to distributor relationships. Foreign currency translation adjustments Patents and Technology [Member] Represents information pertaining to patents and technology. Building and Building Improvements [Member] ulbi_LineOfCreditFacilityMaximumBorrowingCapacityMayBeIncreasedTo Line of Credit Facility Maximum Borrowing Capacity May Be Increased to The maximum borrowing capacity that the company may be increased to according to the credit agreement. us-gaap_TableTextBlock Notes Tables PNC Bank [Member] Represents the PNC Bank. 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Business Acquisition, Acquiree [Domain] Earnings Per Share [Text Block] us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations Net cash provided by (used in) operating activities Business Acquisition [Axis]