Document And Entity Information Changes in operating assets and liabilities: Debt Instrument, Name [Domain] us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Statistical Measurement [Axis] Note To Financial Statement Details Textual Note 2 - Debt Income tax (benefit) provision us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised Exercised, shares (in shares) Note 4 - Supplemental Balance Sheet Information ecd_NonRule10b51ArrTrmntdFlag false Note 5 - Stock-based Compensation ecd_NonRule10b51ArrAdoptedFlag false Note 7 - Operating Leases Depreciation Depreciation expense Trading Arrangements, by Individual [Table] Note 8 - Commitments and Contingencies us-gaap_DebtInstrumentInterestRateEffectivePercentage Debt Instrument, Interest Rate, Effective Percentage Material Terms of Trading Arrangement [Text Block] Note 10 - Business Segment Information Note 2 - Debt - Future Minimum Principal Repayment Obligations (Details) Note 4 - Supplemental Balance Sheet Information - Components of Inventory (Details) Note 4 - Supplemental Balance Sheet Information - Components of Property, Plant and Equipment (Details) Note 4 - Supplemental Balance Sheet Information - Schedule of Depreciation Expense (Details) Minimum [Member] Note 4 - Supplemental Balance Sheet Information - Summary of Goodwill (Details) Note 4 - Supplemental Balance Sheet Information - Composition of Intangible Assets (Details) Statistical Measurement [Domain] Maximum [Member] Note 4 - Supplemental Balance Sheet Information - Amortization of Intangible Assets (Details) Note 5 - Stock-based Compensation - Non-cash Stock Compensation Expense (Details) Schedule of Long-Term Debt Instruments [Table] Note 5 - Stock-based Compensation - Stock Option Activity (Details) Note 7 - Operating Leases - Lease Cost (Details) us-gaap_IncreaseDecreaseInAccountsReceivable Accounts receivable Debt Instrument [Axis] Note 7 - Operating Leases - Supplement Cash Flow Information Related to Leases (Details) Note 7 - Operating Leases - Supplemental Balance Sheet Information Related to Leases (Details) Note 7 - Operating Leases - Future Minimum Lease Payments (Details) Note 8 - Commitments and Contingencies - Changes in Product Warranty Liability (Details) Note 10 - Business Segment Information - Segment Activity (Details) OPERATING ACTIVITIES: Note 10 - Business Segment Information - Revenue by Business Segment Sector (Details) Business Description and Accounting Policies [Text Block] INVESTING ACTIVITIES: us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash provided by operating activities Raw materials FINANCING ACTIVITIES: Work in process us-gaap_NetCashProvidedByUsedInInvestingActivities Net cash used in investing activities Notes To Financial Statements Notes To Financial Statements [Abstract] us-gaap_NetCashProvidedByUsedInFinancingActivities Net cash used in financing activities Finished goods us-gaap_SecuredDebt Secured Debt, Total us-gaap_SecuredDebtCurrent Secured Debt, Total us-gaap_EffectiveIncomeTaxRateContinuingOperations Effective Income Tax Rate Reconciliation, Percent Forfeited or expired, weighted average exercise price (in dollars per share) Granted, weighted average exercise price (in dollars per share) Exercised, weighted average exercise price (in dollars per share) Operating Segments [Member] Income Tax Jurisdiction [Domain] Accounting Policies [Abstract] Segments [Domain] us-gaap_DeferredFinanceCostsGross Debt Issuance Costs, Gross Land [Member] us-gaap_LongTermPurchaseCommitmentAmount Long-Term Purchase Commitment, Amount Trade accounts receivable, allowance for doubtful accounts Segments [Axis] us-gaap_LesseeOperatingLeaseRemainingLeaseTerm Lessee, Operating Lease, Remaining Lease Term (Year) Internal Revenue Service (IRS) [Member] Income Statement [Abstract] us-gaap_IncreaseDecreaseInInventories Inventories us-gaap_UnrecognizedTaxBenefits Unrecognized Tax Benefits, Ending Balance Other Intangible Assets [Member] us-gaap_NumberOfReportableSegments Number of Reportable Segments us-gaap_TreasuryStockCommonValue Treasury stock - at cost; 4,436,114 shares at March 31, 2026 and 4,436,114 shares at December 31, 2025 Segment Reporting [Text Block] Treasury Stock, Common, Shares (in shares) Treasury Stock, Common [Member] Net income attributable to Ultralife (Loss) income attributable to Ultralife Corporation Adjustments to reconcile net income to net cash provided by operating activities: Award Type [Axis] Segment Reporting [Table Text Block] Preferred stock – par value $.10 per share; authorized 1,000,000 shares; none issued us-gaap_Liabilities Total liabilities Plan Name [Axis] Plan Name [Domain] Amortization of financing fees Amortization of intangible assets us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and stockholders’ equity Stock compensation plan expense Consolidation Items [Axis] us-gaap_IncreaseDecreaseInPrepaidExpense Prepaid expenses and other assets Segment Reporting [Table] KeyBank [Member] Related to the lender KeyBank. Condensed Balance Sheet Statement [Table] Selling, general and administrative Stock-based compensation us-gaap_ShareBasedCompensation Consolidation Items [Domain] us-gaap_GoodwillForeignCurrencyTranslationGainLoss Effect of foreign currency translation Income Tax Disclosure [Text Block] Lessee, Lease, Description [Table] Restricted Stock [Member] Lessee, Lease, Cash Flow Information [Table Text Block] Tabular disclosure of cash flow information related lessee's lease . Accounting Standards Update and Change in Accounting Principle [Table] Preferred Stock, Shares Issued (in shares) Lessee, Lease, Balance Sheet Information [Table Text Block] Tabular disclosure of balance sheet information related lessee's lease . Preferred Stock, Shares Authorized (in shares) Preferred stock, par value (in dollars per share) ulbi_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRestrictedStockRequisiteServicePeriodRecognition Stock-based compensation – restricted stock This element represents the amount of recognized equity-based compensation related to restricted stock options during the period. us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect INCREASE (DECREASE) IN CASH Foreign currency translation adjustments adjustments us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents Cash - Beginning of year Cash - End of year Effect of exchange rate changes on cash us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents Supplemental Balance Sheet Disclosures [Text Block] Vested and expected to vest, shares (in shares) Vested and expected to vest, aggregate intrinsic value Statement [Table] Vested and expected, weighted average exercise price (in dollars per share) Exercisable- aggregate intrinsic value Credit Facility [Axis] Operating cash flows from operating leases Credit Facility [Domain] Revolving Credit Facility [Member] Income Tax Authority, Name [Axis] Income Tax Authority, Name [Domain] Government & Defense [Member] Represents information pertaining to the Government and Defense customer. us-gaap_OpenTaxYear Open Tax Year Revenue, percentage The percentage of total revenue for the period. Other expense (income): Right-of-use assets obtained in exchange for lease liabilities: Statement of Financial Position [Abstract] Interest and financing expense us-gaap_DeferredTaxAssetsValuationAllowance Deferred Tax Assets, Valuation Allowance Commercial [Member] Represents information pertaining to the Commercial customer. Other expenses, net Total other expense, net Schedule of Revenues from External Customers by Business Segment Sector [Table Text Block] Tabular disclosure of material revenue from specific sectors of each business segment. Line of Credit Facility, Lender [Domain] Lender Name [Axis] Product and Service [Domain] Product and Service [Axis] us-gaap_LineOfCredit Long-Term Line of Credit, Total 2026 us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Other noncurrent assets us-gaap_OtherAssetsNoncurrent His Majesty's Revenue and Customs (HMRC) [Member] us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue Total lease payments us-gaap_IncreaseDecreaseInDeferredIncomeTaxes Deferred income tax expense Weighted-average discount rate dei_DocumentType Document Type Operating expenses: Document Information [Line Items] Document Quarterly Report us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths 2027 Weighted-average remaining lease term (years) (Year) Document Information [Table] us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount Dilutive Securities Included in Computation of Earnings Per Share Amount Stock Option (in shares) us-gaap_ExtendedProductWarrantyAccrual Extended Product Warranty Accrual Schedule of Maturities of Long-Term Debt [Table Text Block] Potential common shares (in shares) Exercisable, shares (in shares) us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear 2026 dei_EntityInteractiveDataCurrent Entity Interactive Data Current Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber Outstanding, shares (in shares) Outstanding, shares (in shares) us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree 2029 Document Transition Report Weighted average shares outstanding – Diluted (in shares) Nature of Expense [Axis] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice Outstanding, weighted average exercise price (in dollars per share) Outstanding, weighted average exercise price (in dollars per share) us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo 2028 Commitments and Contingencies Disclosure [Text Block] Intangible Asset, Finite-Lived, Amortization Expense [Table Text Block] Statement [Line Items] us-gaap_OperatingExpenses Total operating expenses Operating Expenses Outstanding- aggregate intrinsic value us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour 2030 Common stock, shares issued (in shares) Purchase Commitment, Excluding Long-Term Commitment [Domain] Common stock, shares outstanding (in shares) Balance (in shares) Balance (in shares) Award Type [Domain] Income Tax Jurisdiction, Foreign, Other [Member] Common Stock, Shares Authorized (in shares) Purchase Commitment, Excluding Long-Term Commitment [Axis] us-gaap_ExtendedProductWarrantyAccrualNoncurrent Extended Product Warranty Accrual, Noncurrent us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Weighted average shares outstanding – Basic (in shares) us-gaap_ExtendedProductWarrantyAccrualCurrent Extended Product Warranty Accrual, Current us-gaap_DebtInstrumentTerm Debt Instrument, Term Net (loss) income per share attributable to Ultralife Corporation common stockholders – Basic (in dollars per share) Earnings Per Share, Basic, by Common Class, Including Two-Class Method [Table] Schedule of Product Warranty Liability [Table Text Block] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Common stock – par value $.10 per share; authorized 40,000,000 shares; issued – 21,092,617 shares at March 31, 2026 and 21,092,617 shares at December 31, 2025; outstanding – 16,656,503 shares at March 31, 2026 and 16,656,503 shares at December 31, 2025 Effective Income Tax Rate Reconciliation [Table] Schedule of Inventory, Current [Table Text Block] Accounts payable us-gaap_AccountsPayableCurrent Income Tax Jurisdiction [Axis] us-gaap_PolicyTextBlockAbstract Accounting Policies us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements us-gaap_TableTextBlock Notes Tables Computer Equipment [Member] us-gaap_FiniteLivedIntangibleAssetsNet Net Document Fiscal Period Focus us-gaap_FiniteLivedIntangibleAssetsGross Cost Customer [Domain] Document Fiscal Year Focus us-gaap_ComprehensiveIncomeNetOfTax Comprehensive (loss) income attributable to Ultralife Corporation Amendment Flag Common Stock [Member] Goodwill Balance Balance dei_DocumentPeriodEndDate Document Period End Date Patented Technology [Member] Selling, General and Administrative [Member] Represents the Selling, general and administrative expenses. Long-Lived Asset, Class [Domain] Research and Development [Member] Represents the Research and development expenses. Granted, shares (in shares) Variable lease cost Legal Entity [Axis] Accrued compensation and related benefits us-gaap_EmployeeRelatedLiabilitiesCurrent Operating lease cost Construction in Progress [Member] us-gaap_LeaseCost Total lease cost us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount Less: Imputed interest dei_EntityFileNumber Entity File Number Payments on credit facilities Outstanding- weighted average remaining contractual term (Year) Operating lease liability, net of current portion ulbi_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour Thereafter Amount of lessee's undiscounted obligation for lease payment for operating lease due after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Schedule of Depreciation Expense [Table Text Block] Tabular disclosure of the depreciation expense. Entity Tax Identification Number us-gaap_OperatingLeaseLiability Total operating lease liability Present value of remaining lease payments Current operating lease liability Disaggregation of Revenue [Table] Entity [Domain] Entity Central Index Key Vested and expected to vest, weighted average remaining contractual term (Year) dei_EntityRegistrantName Entity Registrant Name Capital Addition Purchase Commitments [Member] The amount of capital addition purchase commitments. Foreign currency translation adjustments dei_EntityCurrentReportingStatus Entity Current Reporting Status Entity Incorporation, State or Country Code Current portion of long-term debt Current Fiscal Year End Date Exercisable- weighted average remaining contractual term (Year) Other intangible assets, net 2028 Long-term debt, net us-gaap_ResearchAndDevelopmentExpense Research and development Research and development Entity Filer Category dei_EntityShellCompany Entity Shell Company 2029 Entity Emerging Growth Company 2027 Entity Small Business Building and Building Improvements [Member] Segment contribution Operating (loss) income Operating Income Income Tax Jurisdiction, Domestic Federal [Member] Cash us-gaap_Cash us-gaap_OperatingLossCarryforwards Operating Loss Carryforwards The 2024 Long-term Incentive Plan [Member] In regards to the The 2024 Long-term Incentive Plan. Income Tax Jurisdiction, Domestic State and Local [Member] us-gaap_LongTermDebt Total us-gaap_ContractWithCustomerLiabilityRevenueRecognized Contract with Customer, Liability, Revenue Recognized Revenues us-gaap_Revenues Net (loss) income attributable to Ultralife Corporation Accounts payable and other liabilities Entity Address, State or Province Statement of Stockholders' Equity [Abstract] Intangible Asset, Finite-Lived, Class [Axis] Entity Address, City or Town Inventory, Current [Table] Accumulated deficit Intangible Asset, Finite-Lived, Class [Domain] Entity Address, Address Line One Statement of Cash Flows [Abstract] City Area Code Local Phone Number Entity Address, Postal Zip Code Revenue from Contract with Customer [Text Block] dei_Security12bTitle Title of 12(b) Security Equity Components [Axis] Security Exchange Name dei_TradingSymbol Trading Symbol us-gaap_ProceedsFromStockOptionsExercised Proceeds from Stock Options Exercised Class of Stock [Axis] Equity Component [Domain] us-gaap_ProductWarrantyAccrualPayments Settlements made Accruals for warranties issued AOCI Attributable to Parent [Member] dei_EntityCommonStockSharesOutstanding Entity Common Stock, Shares Outstanding (in shares) Additional Paid-in Capital [Member] Retained Earnings [Member] us-gaap_ProductWarrantyAccrual Accrued warranty obligations – beginning Accrued warranty obligations – ending Earnings Per Share [Text Block] Income Tax Jurisdiction, Foreign [Member] Property, plant and equipment, net Property, plant and equipment, net Net (loss) income attributable to non-controlling interest Property, plant and equipment, gross Net (loss) income Net (loss) income Scenario [Axis] Scenario [Domain] Deferred income taxes, net Forecast [Member] Machinery and Equipment [Member] Exercisable, weighted average exercise price (in dollars per share) Property, Plant, and Equipment [Table] Cost of products sold Cost of products sold Common stock, par value (in dollars per share) Furniture and Fixtures [Member] Stockholders’ equity: us-gaap_OtherNonoperatingIncomeExpense Miscellaneous income Long-Lived Asset, Class [Axis] Share-Based Payment Arrangement, Option, Activity [Table Text Block] Total assets Total assets Deferred income taxes Geographical [Domain] Geographical [Axis] Share-Based Payment Arrangement, Option [Member] Current liabilities: us-gaap_LiabilitiesCurrent Total current liabilities Net (loss) income per share attributable to Ultralife Corporation common stockholders – Diluted (in dollars per share) Customer [Axis] Trade accounts receivable, net of allowance for expected credit losses of $461 and $457, respectively us-gaap_TaxCreditCarryforwardAmount Tax Credit Carryforward, Amount Certain Communications Systems Products [Member] Represents certain Communications Systems products. Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] Lease, Cost [Table Text Block] ulbi_ExtendedProductWarrantyTerm Extended Product Warranty, Term Term of the extended product warranty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod Forfeited or expired, shares (in shares) Customer Relationships [Member] Other Commitments [Table] us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment Less: Accumulated depreciation Accumulated other comprehensive loss Intangible Asset, Finite-Lived [Table Text Block] Stock-based compensation – stock options Intangible Asset, Finite-Lived [Table] us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization Accumulated Amortization Interim Period, Costs Not Allocable [Domain] Shareholders' Equity and Share-Based Payments [Text Block] us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest Total stockholders’ equity Balance Balance ulbi_MaximumConsolidatedSeniorLeverageRatio Maximum Consolidated Senior Leverage Ratio Represents information related to consolidated senior leverage ratio. Term Loan Facility [Member] Represents information related to term loan facility. Amended Credit Agreement [Member] Represents information related to Amended Credit Agreement. Inventories, net Total Long-term Debt, Current Maturities [Member] Represents Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligation us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest (Loss) income before income taxes Noncontrolling Interest [Member] Capital in excess of par value us-gaap_StockholdersEquity Total Ultralife Corporation equity Debt Disclosure [Text Block] Communications Systems Segment [Member] Represents the company's communications systems segment. Goodwill [Table Text Block] Non-controlling interest Battery & Energy Products Segment [Member] Represents the company's battery & energy products segment. Prepaid expenses and other current assets us-gaap_PrepaidExpenseAndOtherAssetsCurrent us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1 Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Depreciation and amortization of intangible assets us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1 Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) us-gaap_PaymentsToAcquirePropertyPlantAndEquipment Purchases of property, plant and equipment Lessee, Operating Leases [Text Block] UNITED STATES Non-US [Member] us-gaap_DebtInstrumentFaceAmount Debt Instrument, Face Amount Disclosure of Share-Based Compensation Arrangements by Share-Based Payment Award [Table Text Block] Current assets: Operating lease right-of-use asset Accrued expenses and other current liabilities us-gaap_OtherLiabilitiesCurrent us-gaap_AssetsCurrent Total current assets Other noncurrent liabilities us-gaap_OtherLiabilitiesNoncurrent ecd_Rule10b51ArrTrmntdFlag false Property, Plant, and Equipment [Table Text Block] Revenues Gross profit Gross profit ecd_Rule10b51ArrAdoptedFlag false Commitments and Contingencies Goodwill [Table]