3.20.4 html 1196 949 1 false 277 0 false 10 false false R1.htm 00090 - Document - Document and Entity Information Sheet http://www.ibm.com/role/DocumentDocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 00100 - Statement - CONSOLIDATED INCOME STATEMENT Sheet http://www.ibm.com/role/StatementConsolidatedIncomeStatement CONSOLIDATED INCOME STATEMENT Statements 2 false false R3.htm 00200 - Statement - CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME Sheet http://www.ibm.com/role/StatementConsolidatedStatementOfComprehensiveIncome CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME Statements 3 false false R4.htm 00300 - Statement - CONSOLIDATED BALANCE SHEET Sheet http://www.ibm.com/role/StatementConsolidatedBalanceSheet CONSOLIDATED BALANCE SHEET Statements 4 false false R5.htm 00305 - Statement - CONSOLIDATED BALANCE SHEET (Parenthetical) Sheet http://www.ibm.com/role/StatementConsolidatedBalanceSheetParenthetical CONSOLIDATED BALANCE SHEET (Parenthetical) Statements 5 false false R6.htm 00400 - Statement - CONSOLIDATED STATEMENT OF CASH FLOWS Sheet http://www.ibm.com/role/StatementConsolidatedStatementOfCashFlows CONSOLIDATED STATEMENT OF CASH FLOWS Statements 6 false false R7.htm 00500 - Statement - CONSOLIDATED STATEMENT OF EQUITY Sheet http://www.ibm.com/role/StatementConsolidatedStatementOfEquity CONSOLIDATED STATEMENT OF EQUITY Statements 7 false false R8.htm 00505 - Statement - CONSOLIDATED STATEMENT OF EQUITY (Parenthetical) Sheet http://www.ibm.com/role/StatementConsolidatedStatementOfEquityParenthetical CONSOLIDATED STATEMENT OF EQUITY (Parenthetical) Statements 8 false false R9.htm 10101 - Disclosure - Significant Accounting Policies Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPolicies Significant Accounting Policies Notes 9 false false R10.htm 10201 - Disclosure - Accounting Changes Sheet http://www.ibm.com/role/DisclosureAccountingChanges Accounting Changes Notes 10 false false R11.htm 10301 - Disclosure - Revenue Recognition Sheet http://www.ibm.com/role/DisclosureRevenueRecognition Revenue Recognition Notes 11 false false R12.htm 10401 - Disclosure - Segments Sheet http://www.ibm.com/role/DisclosureSegments Segments Notes 12 false false R13.htm 10501 - Disclosure - Acquisitions & Divestitures Sheet http://www.ibm.com/role/DisclosureAcquisitionsDivestitures Acquisitions & Divestitures Notes 13 false false R14.htm 10601 - Disclosure - Research, Development & Engineering Sheet http://www.ibm.com/role/DisclosureResearchDevelopmentEngineering Research, Development & Engineering Notes 14 false false R15.htm 10701 - Disclosure - Taxes Sheet http://www.ibm.com/role/DisclosureTaxes Taxes Notes 15 false false R16.htm 10801 - Disclosure - Earnings Per Share Sheet http://www.ibm.com/role/DisclosureEarningsPerShare Earnings Per Share Notes 16 false false R17.htm 10901 - Disclosure - Financial Assets & Liabilities Sheet http://www.ibm.com/role/DisclosureFinancialAssetsLiabilities Financial Assets & Liabilities Notes 17 false false R18.htm 11001 - Disclosure - Inventory Sheet http://www.ibm.com/role/DisclosureInventory Inventory Notes 18 false false R19.htm 11101 - Disclosure - Financing Receivables Sheet http://www.ibm.com/role/DisclosureFinancingReceivables Financing Receivables Notes 19 false false R20.htm 11201 - Disclosure - Property, Plant & Equipment Sheet http://www.ibm.com/role/DisclosurePropertyPlantEquipment Property, Plant & Equipment Notes 20 false false R21.htm 11301 - Disclosure - Leases Sheet http://www.ibm.com/role/DisclosureLeases Leases Notes 21 false false R22.htm 11401 - Disclosure - Intangible Assets Including Goodwill Sheet http://www.ibm.com/role/DisclosureIntangibleAssetsIncludingGoodwill Intangible Assets Including Goodwill Notes 22 false false R23.htm 11501 - Disclosure - Investments & Sundry Assets Sheet http://www.ibm.com/role/DisclosureInvestmentsSundryAssets Investments & Sundry Assets Notes 23 false false R24.htm 11601 - Disclosure - Borrowings Sheet http://www.ibm.com/role/DisclosureBorrowings Borrowings Notes 24 false false R25.htm 11701 - Disclosure - Other Liabilities Sheet http://www.ibm.com/role/DisclosureOtherLiabilities Other Liabilities Notes 25 false false R26.htm 11801 - Disclosure - Commitments & Contingencies Sheet http://www.ibm.com/role/DisclosureCommitmentsContingencies Commitments & Contingencies Notes 26 false false R27.htm 11901 - Disclosure - Equity Activity Sheet http://www.ibm.com/role/DisclosureEquityActivity Equity Activity Notes 27 false false R28.htm 12001 - Disclosure - Derivative Financial Instruments Sheet http://www.ibm.com/role/DisclosureDerivativeFinancialInstruments Derivative Financial Instruments Notes 28 false false R29.htm 12101 - Disclosure - Stock-Based Compensation Sheet http://www.ibm.com/role/DisclosureStockBasedCompensation Stock-Based Compensation Notes 29 false false R30.htm 12201 - Disclosure - Retirement-Related Benefits Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefits Retirement-Related Benefits Notes 30 false false R31.htm 12301 - Disclosure - Subsequent Events Sheet http://www.ibm.com/role/DisclosureSubsequentEvents Subsequent Events Notes 31 false false R32.htm 12401 - Disclosure - SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS AND RESERVES Sheet http://www.ibm.com/role/DisclosureScheduleIiValuationAndQualifyingAccountsAndReserves SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS AND RESERVES Notes 32 false false R33.htm 20102 - Disclosure - Significant Accounting Policies (Policies) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesPolicies Significant Accounting Policies (Policies) Policies http://www.ibm.com/role/DisclosureSignificantAccountingPolicies 33 false false R34.htm 30303 - Disclosure - Revenue Recognition (Tables) Sheet http://www.ibm.com/role/DisclosureRevenueRecognitionTables Revenue Recognition (Tables) Tables http://www.ibm.com/role/DisclosureRevenueRecognition 34 false false R35.htm 30403 - Disclosure - Segments (Tables) Sheet http://www.ibm.com/role/DisclosureSegmentsTables Segments (Tables) Tables http://www.ibm.com/role/DisclosureSegments 35 false false R36.htm 30503 - Disclosure - Acquisitions & Divestitures (Tables) Sheet http://www.ibm.com/role/DisclosureAcquisitionsDivestituresTables Acquisitions & Divestitures (Tables) Tables http://www.ibm.com/role/DisclosureAcquisitionsDivestitures 36 false false R37.htm 30703 - Disclosure - Taxes (Tables) Sheet http://www.ibm.com/role/DisclosureTaxesTables Taxes (Tables) Tables http://www.ibm.com/role/DisclosureTaxes 37 false false R38.htm 30803 - Disclosure - Earnings Per Share (Tables) Sheet http://www.ibm.com/role/DisclosureEarningsPerShareTables Earnings Per Share (Tables) Tables http://www.ibm.com/role/DisclosureEarningsPerShare 38 false false R39.htm 30903 - Disclosure - Financial Assets & Liabilities (Tables) Sheet http://www.ibm.com/role/DisclosureFinancialAssetsLiabilitiesTables Financial Assets & Liabilities (Tables) Tables http://www.ibm.com/role/DisclosureFinancialAssetsLiabilities 39 false false R40.htm 31003 - Disclosure - Inventory (Tables) Sheet http://www.ibm.com/role/DisclosureInventoryTables Inventory (Tables) Tables http://www.ibm.com/role/DisclosureInventory 40 false false R41.htm 31103 - Disclosure - Financing Receivables (Tables) Sheet http://www.ibm.com/role/DisclosureFinancingReceivablesTables Financing Receivables (Tables) Tables http://www.ibm.com/role/DisclosureFinancingReceivables 41 false false R42.htm 31203 - Disclosure - Property, Plant & Equipment (Tables) Sheet http://www.ibm.com/role/DisclosurePropertyPlantEquipmentTables Property, Plant & Equipment (Tables) Tables http://www.ibm.com/role/DisclosurePropertyPlantEquipment 42 false false R43.htm 31303 - Disclosure - Leases (Tables) Sheet http://www.ibm.com/role/DisclosureLeasesTables Leases (Tables) Tables http://www.ibm.com/role/DisclosureLeases 43 false false R44.htm 31403 - Disclosure - Intangible Assets Including Goodwill (Tables) Sheet http://www.ibm.com/role/DisclosureIntangibleAssetsIncludingGoodwillTables Intangible Assets Including Goodwill (Tables) Tables http://www.ibm.com/role/DisclosureIntangibleAssetsIncludingGoodwill 44 false false R45.htm 31503 - Disclosure - Investments & Sundry Assets (Tables) Sheet http://www.ibm.com/role/DisclosureInvestmentsSundryAssetsTables Investments & Sundry Assets (Tables) Tables http://www.ibm.com/role/DisclosureInvestmentsSundryAssets 45 false false R46.htm 31603 - Disclosure - Borrowings (Tables) Sheet http://www.ibm.com/role/DisclosureBorrowingsTables Borrowings (Tables) Tables http://www.ibm.com/role/DisclosureBorrowings 46 false false R47.htm 31703 - Disclosure - Other Liabilities (Tables) Sheet http://www.ibm.com/role/DisclosureOtherLiabilitiesTables Other Liabilities (Tables) Tables http://www.ibm.com/role/DisclosureOtherLiabilities 47 false false R48.htm 31803 - Disclosure - Commitments & Contingencies (Tables) Sheet http://www.ibm.com/role/DisclosureCommitmentsContingenciesTables Commitments & Contingencies (Tables) Tables http://www.ibm.com/role/DisclosureCommitmentsContingencies 48 false false R49.htm 31903 - Disclosure - Equity Activity (Tables) Sheet http://www.ibm.com/role/DisclosureEquityActivityTables Equity Activity (Tables) Tables http://www.ibm.com/role/DisclosureEquityActivity 49 false false R50.htm 32003 - Disclosure - Derivative Financial Instruments (Tables) Sheet http://www.ibm.com/role/DisclosureDerivativeFinancialInstrumentsTables Derivative Financial Instruments (Tables) Tables http://www.ibm.com/role/DisclosureDerivativeFinancialInstruments 50 false false R51.htm 32103 - Disclosure - Stock-Based Compensation (Tables) Sheet http://www.ibm.com/role/DisclosureStockBasedCompensationTables Stock-Based Compensation (Tables) Tables http://www.ibm.com/role/DisclosureStockBasedCompensation 51 false false R52.htm 32203 - Disclosure - Retirement-Related Benefits (Tables) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsTables Retirement-Related Benefits (Tables) Tables http://www.ibm.com/role/DisclosureRetirementRelatedBenefits 52 false false R53.htm 40101 - Disclosure - Significant Accounting Policies - Basis of Presentation (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesBasisOfPresentationDetails Significant Accounting Policies - Basis of Presentation (Details) Details 53 false false R54.htm 40102 - Disclosure - Significant Accounting Policies - Billing and Financing Components (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesBillingAndFinancingComponentsDetails Significant Accounting Policies - Billing and Financing Components (Details) Details 54 false false R55.htm 40103 - Disclosure - Significant Accounting Policies - Revenue Recognition for Major Categories of Revenue (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesRevenueRecognitionForMajorCategoriesOfRevenueDetails Significant Accounting Policies - Revenue Recognition for Major Categories of Revenue (Details) Details 55 false false R56.htm 40104 - Disclosure - Significant Accounting Policies - Software Costs (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesSoftwareCostsDetails Significant Accounting Policies - Software Costs (Details) Details 56 false false R57.htm 40105 - Disclosure - Significant Accounting Policies - Incremental Costs of Obtaining a Contract (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesIncrementalCostsOfObtainingContractDetails Significant Accounting Policies - Incremental Costs of Obtaining a Contract (Details) Details 57 false false R58.htm 40106 - Disclosure - Significant Accounting Policies - Product Warranties (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesProductWarrantiesDetails Significant Accounting Policies - Product Warranties (Details) Details 58 false false R59.htm 40107 - Disclosure - Significant Accounting Policies - Advertising and Promotional Expense (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesAdvertisingAndPromotionalExpenseDetails Significant Accounting Policies - Advertising and Promotional Expense (Details) Details 59 false false R60.htm 40108 - Disclosure - Significant Accounting Policies - Depreciation (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesDepreciationDetails Significant Accounting Policies - Depreciation (Details) Details 60 false false R61.htm 40109 - Disclosure - Significant Accounting Policies - Amortization (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesAmortizationDetails Significant Accounting Policies - Amortization (Details) Details 61 false false R62.htm 40110 - Disclosure - Significant Accounting Policies - Stock-Based Compensation (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesStockBasedCompensationDetails Significant Accounting Policies - Stock-Based Compensation (Details) Details 62 false false R63.htm 40111 - Disclosure - Significant Accounting Policies - Fair Value Measurement (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesFairValueMeasurementDetails Significant Accounting Policies - Fair Value Measurement (Details) Details 63 false false R64.htm 40112 - Disclosure - Significant Accounting Policies - Transfers of Financial Assets (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesTransfersOfFinancialAssetsDetails Significant Accounting Policies - Transfers of Financial Assets (Details) Details 64 false false R65.htm 40113 - Disclosure - Significant Accounting Policies - Financing Receivables (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesFinancingReceivablesDetails Significant Accounting Policies - Financing Receivables (Details) Details 65 false false R66.htm 40114 - Disclosure - Significant Accounting Policies - Leases (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesLeasesDetails Significant Accounting Policies - Leases (Details) Details 66 false false R67.htm 40115 - Disclosure - Significant Accounting Policies - Common Stock (Details) Sheet http://www.ibm.com/role/DisclosureSignificantAccountingPoliciesCommonStockDetails Significant Accounting Policies - Common Stock (Details) Details 67 false false R68.htm 40201 - Disclosure - Accounting Changes - Credit Losses (Details) Sheet http://www.ibm.com/role/DisclosureAccountingChangesCreditLossesDetails Accounting Changes - Credit Losses (Details) Details 68 false false R69.htm 40202 - Disclosure - Accounting Changes - Leases (Details) Sheet http://www.ibm.com/role/DisclosureAccountingChangesLeasesDetails Accounting Changes - Leases (Details) Details 69 false false R70.htm 40203 - Disclosure - Accounting Changes - Revenue Recognition (Details) Sheet http://www.ibm.com/role/DisclosureAccountingChangesRevenueRecognitionDetails Accounting Changes - Revenue Recognition (Details) Details 70 false false R71.htm 40301 - Disclosure - Revenue Recognition - Disaggregation of Revenue by Major Products/Service Offerings (Details) Sheet http://www.ibm.com/role/DisclosureRevenueRecognitionDisaggregationOfRevenueByMajorProductsServiceOfferingsDetails Revenue Recognition - Disaggregation of Revenue by Major Products/Service Offerings (Details) Details 71 false false R72.htm 40302 - Disclosure - Revenue Recognition - Disaggregation of Revenue by Geography (Details) Sheet http://www.ibm.com/role/DisclosureRevenueRecognitionDisaggregationOfRevenueByGeographyDetails Revenue Recognition - Disaggregation of Revenue by Geography (Details) Details 72 false false R73.htm 40303 - Disclosure - Revenue Recognition - Remaining Performance Obligations (Details) Sheet http://www.ibm.com/role/DisclosureRevenueRecognitionRemainingPerformanceObligationsDetails Revenue Recognition - Remaining Performance Obligations (Details) Details 73 false false R74.htm 40304 - Disclosure - Revenue Recognition - Remaining Performance Obligations, Expected Timing of Satisfaction (Details) Sheet http://www.ibm.com/role/DisclosureRevenueRecognitionRemainingPerformanceObligationsExpectedTimingOfSatisfactionDetails Revenue Recognition - Remaining Performance Obligations, Expected Timing of Satisfaction (Details) Details 74 false false R75.htm 40305 - Disclosure - Revenue Recognition - Performance Obligations Satisfied or Partially Satisfied in Prior Periods (Details) Sheet http://www.ibm.com/role/DisclosureRevenueRecognitionPerformanceObligationsSatisfiedOrPartiallySatisfiedInPriorPeriodsDetails Revenue Recognition - Performance Obligations Satisfied or Partially Satisfied in Prior Periods (Details) Details 75 false false R76.htm 40306 - Disclosure - Revenue Recognition - Reconciliation of Contract Balances (Details) Sheet http://www.ibm.com/role/DisclosureRevenueRecognitionReconciliationOfContractBalancesDetails Revenue Recognition - Reconciliation of Contract Balances (Details) Details 76 false false R77.htm 40307 - Disclosure - Revenue Recognition - Trade Allowance for Credit Losses (Details) Sheet http://www.ibm.com/role/DisclosureRevenueRecognitionTradeAllowanceForCreditLossesDetails Revenue Recognition - Trade Allowance for Credit Losses (Details) Details 77 false false R78.htm 40308 - Disclosure - Revenue Recognition - Deferred Contract Costs (Details) Sheet http://www.ibm.com/role/DisclosureRevenueRecognitionDeferredContractCostsDetails Revenue Recognition - Deferred Contract Costs (Details) Details 78 false false R79.htm 40401 - Disclosure - Segments - Results of Continuing Operations (Details) Sheet http://www.ibm.com/role/DisclosureSegmentsResultsOfContinuingOperationsDetails Segments - Results of Continuing Operations (Details) Details 79 false false R80.htm 40402 - Disclosure - Segments - Revenue Reconciliation (Details) Sheet http://www.ibm.com/role/DisclosureSegmentsRevenueReconciliationDetails Segments - Revenue Reconciliation (Details) Details 80 false false R81.htm 40403 - Disclosure - Segments - Pre-Tax Income Reconciliation (Details) Sheet http://www.ibm.com/role/DisclosureSegmentsPreTaxIncomeReconciliationDetails Segments - Pre-Tax Income Reconciliation (Details) Details 81 false false R82.htm 40404 - Disclosure - Segments - Assets and Other Items (Details) Sheet http://www.ibm.com/role/DisclosureSegmentsAssetsAndOtherItemsDetails Segments - Assets and Other Items (Details) Details 82 false false R83.htm 40405 - Disclosure - Segments - Asset Reconciliation (Details) Sheet http://www.ibm.com/role/DisclosureSegmentsAssetReconciliationDetails Segments - Asset Reconciliation (Details) Details 83 false false R84.htm 40406 - Disclosure - Segments - Geographic Information (Details) Sheet http://www.ibm.com/role/DisclosureSegmentsGeographicInformationDetails Segments - Geographic Information (Details) Details 84 false false R85.htm 40407 - Disclosure - Segments - Revenue by Product or Service (Details) Sheet http://www.ibm.com/role/DisclosureSegmentsRevenueByProductOrServiceDetails Segments - Revenue by Product or Service (Details) Details 85 false false R86.htm 40501 - Disclosure - Acquisitions & Divestitures - (Details) Sheet http://www.ibm.com/role/DisclosureAcquisitionsDivestituresDetails Acquisitions & Divestitures - (Details) Details http://www.ibm.com/role/DisclosureAcquisitionsDivestituresTables 86 false false R87.htm 40502 - Disclosure - Acquisitions & Divestitures - Purchase Price Allocation 2020 (Details) Sheet http://www.ibm.com/role/DisclosureAcquisitionsDivestituresPurchasePriceAllocation2020Details Acquisitions & Divestitures - Purchase Price Allocation 2020 (Details) Details 87 false false R88.htm 40503 - Disclosure - Acquisitions & Divestitures - 2019 Acquisitions (Details) Sheet http://www.ibm.com/role/DisclosureAcquisitionsDivestitures2019AcquisitionsDetails Acquisitions & Divestitures - 2019 Acquisitions (Details) Details 88 false false R89.htm 40504 - Disclosure - Acquisitions & Divestitures - Purchase Price Allocation 2019 (Details) Sheet http://www.ibm.com/role/DisclosureAcquisitionsDivestituresPurchasePriceAllocation2019Details Acquisitions & Divestitures - Purchase Price Allocation 2019 (Details) Details 89 false false R90.htm 40505 - Disclosure - Acquisitions & Divestitures - Goodwill (Details) Sheet http://www.ibm.com/role/DisclosureAcquisitionsDivestituresGoodwillDetails Acquisitions & Divestitures - Goodwill (Details) Details 90 false false R91.htm 40506 - Disclosure - Acquisitions & Divestitures - Pro forma information (Details) Sheet http://www.ibm.com/role/DisclosureAcquisitionsDivestituresProFormaInformationDetails Acquisitions & Divestitures - Pro forma information (Details) Details 91 false false R92.htm 40507 - Disclosure - Acquisitions & Divestitures - 2018 Acquisitions (Details) Sheet http://www.ibm.com/role/DisclosureAcquisitionsDivestitures2018AcquisitionsDetails Acquisitions & Divestitures - 2018 Acquisitions (Details) Details 92 false false R93.htm 40508 - Disclosure - Acquisitions & Divestitures - Divestitures (Details) Sheet http://www.ibm.com/role/DisclosureAcquisitionsDivestituresDivestituresDetails Acquisitions & Divestitures - Divestitures (Details) Details 93 false false R94.htm 40601 - Disclosure - Research, Development & Engineering (Details) Sheet http://www.ibm.com/role/DisclosureResearchDevelopmentEngineeringDetails Research, Development & Engineering (Details) Details http://www.ibm.com/role/DisclosureResearchDevelopmentEngineering 94 false false R95.htm 40701 - Disclosure - Taxes - Income before Income Taxes (Details) Sheet http://www.ibm.com/role/DisclosureTaxesIncomeBeforeIncomeTaxesDetails Taxes - Income before Income Taxes (Details) Details 95 false false R96.htm 40702 - Disclosure - Taxes - Provision by Geographic Operations (Details) Sheet http://www.ibm.com/role/DisclosureTaxesProvisionByGeographicOperationsDetails Taxes - Provision by Geographic Operations (Details) Details 96 false false R97.htm 40703 - Disclosure - Taxes - Provision by Taxing Jurisdiction (Details) Sheet http://www.ibm.com/role/DisclosureTaxesProvisionByTaxingJurisdictionDetails Taxes - Provision by Taxing Jurisdiction (Details) Details 97 false false R98.htm 40704 - Disclosure - Taxes - Tax Rate Reconciliation (Details) Sheet http://www.ibm.com/role/DisclosureTaxesTaxRateReconciliationDetails Taxes - Tax Rate Reconciliation (Details) Details 98 false false R99.htm 40705 - Disclosure - Taxes - Tax Rate Reconciliation Narrative (Details) Sheet http://www.ibm.com/role/DisclosureTaxesTaxRateReconciliationNarrativeDetails Taxes - Tax Rate Reconciliation Narrative (Details) Details 99 false false R100.htm 40706 - Disclosure - Taxes - Deferred Taxes (Details) Sheet http://www.ibm.com/role/DisclosureTaxesDeferredTaxesDetails Taxes - Deferred Taxes (Details) Details 100 false false R101.htm 40707 - Disclosure - Taxes - Carryforwards (Details) Sheet http://www.ibm.com/role/DisclosureTaxesCarryforwardsDetails Taxes - Carryforwards (Details) Details 101 false false R102.htm 40708 - Disclosure - Taxes - Unrecognized Tax Benefits Reconciliation (Details) Sheet http://www.ibm.com/role/DisclosureTaxesUnrecognizedTaxBenefitsReconciliationDetails Taxes - Unrecognized Tax Benefits Reconciliation (Details) Details 102 false false R103.htm 40709 - Disclosure - Taxes - Unrecognized Tax Benefits Additional Disclosures (Details) Sheet http://www.ibm.com/role/DisclosureTaxesUnrecognizedTaxBenefitsAdditionalDisclosuresDetails Taxes - Unrecognized Tax Benefits Additional Disclosures (Details) Details 103 false false R104.htm 40710 - Disclosure - Taxes - Income Tax Assessments (Details) Sheet http://www.ibm.com/role/DisclosureTaxesIncomeTaxAssessmentsDetails Taxes - Income Tax Assessments (Details) Details 104 false false R105.htm 40711 - Disclosure - Taxes - Undistributed Foreign Earnings (Details) Sheet http://www.ibm.com/role/DisclosureTaxesUndistributedForeignEarningsDetails Taxes - Undistributed Foreign Earnings (Details) Details 105 false false R106.htm 40801 - Disclosure - Earnings Per Share - Computation (Details) Sheet http://www.ibm.com/role/DisclosureEarningsPerShareComputationDetails Earnings Per Share - Computation (Details) Details 106 false false R107.htm 40802 - Disclosure - Earnings Per Share - Antidilutive Stock Options (Details) Sheet http://www.ibm.com/role/DisclosureEarningsPerShareAntidilutiveStockOptionsDetails Earnings Per Share - Antidilutive Stock Options (Details) Details 107 false false R108.htm 40901 - Disclosure - Financial Assets & Liabilities - Fair Value Measurements (Details) Sheet http://www.ibm.com/role/DisclosureFinancialAssetsLiabilitiesFairValueMeasurementsDetails Financial Assets & Liabilities - Fair Value Measurements (Details) Details 108 false false R109.htm 40902 - Disclosure - Financial Assets & Liabilities - Not Measured at Fair Value (Details) Sheet http://www.ibm.com/role/DisclosureFinancialAssetsLiabilitiesNotMeasuredAtFairValueDetails Financial Assets & Liabilities - Not Measured at Fair Value (Details) Details 109 false false R110.htm 41001 - Disclosure - Inventory (Details) Sheet http://www.ibm.com/role/DisclosureInventoryDetails Inventory (Details) Details http://www.ibm.com/role/DisclosureInventoryTables 110 false false R111.htm 41101 - Disclosure - Financing Receivables - Payment Terms (Details) Sheet http://www.ibm.com/role/DisclosureFinancingReceivablesPaymentTermsDetails Financing Receivables - Payment Terms (Details) Details 111 false false R112.htm 41102 - Disclosure - Financing Receivables - Components of Financing Receivables (Details) Sheet http://www.ibm.com/role/DisclosureFinancingReceivablesComponentsOfFinancingReceivablesDetails Financing Receivables - Components of Financing Receivables (Details) Details 112 false false R113.htm 41103 - Disclosure - Financing Receivables - By Portfolio Segment (Details) Sheet http://www.ibm.com/role/DisclosureFinancingReceivablesByPortfolioSegmentDetails Financing Receivables - By Portfolio Segment (Details) Details 113 false false R114.htm 41104 - Disclosure - Financing Receivables - Past Due (Details) Sheet http://www.ibm.com/role/DisclosureFinancingReceivablesPastDueDetails Financing Receivables - Past Due (Details) Details 114 false false R115.htm 41105 - Disclosure - Financing Receivables - Credit Quality Year of Origination (Details) Sheet http://www.ibm.com/role/DisclosureFinancingReceivablesCreditQualityYearOfOriginationDetails Financing Receivables - Credit Quality Year of Origination (Details) Details 115 false false R116.htm 41106 - Disclosure - Financing Receivables - Credit Quality Indicators (Details) Sheet http://www.ibm.com/role/DisclosureFinancingReceivablesCreditQualityIndicatorsDetails Financing Receivables - Credit Quality Indicators (Details) Details 116 false false R117.htm 41201 - Disclosure - Property, Plant & Equipment (Details) Sheet http://www.ibm.com/role/DisclosurePropertyPlantEquipmentDetails Property, Plant & Equipment (Details) Details http://www.ibm.com/role/DisclosurePropertyPlantEquipmentTables 117 false false R118.htm 41301 - Disclosure - Leases - Components of Lease Costs (Details) Sheet http://www.ibm.com/role/DisclosureLeasesComponentsOfLeaseCostsDetails Leases - Components of Lease Costs (Details) Details 118 false false R119.htm 41302 - Disclosure - Leases - Cash Flow From Lease Transactions (Details) Sheet http://www.ibm.com/role/DisclosureLeasesCashFlowFromLeaseTransactionsDetails Leases - Cash Flow From Lease Transactions (Details) Details 119 false false R120.htm 41303 - Disclosure - Leases - Weighted-average Lease Terms and Discount Rates (Details) Sheet http://www.ibm.com/role/DisclosureLeasesWeightedAverageLeaseTermsAndDiscountRatesDetails Leases - Weighted-average Lease Terms and Discount Rates (Details) Details 120 false false R121.htm 41304 - Disclosure - Leases - Maturity Analysis of Undiscounted Cash Out Flows (Details) Sheet http://www.ibm.com/role/DisclosureLeasesMaturityAnalysisOfUndiscountedCashOutFlowsDetails Leases - Maturity Analysis of Undiscounted Cash Out Flows (Details) Details 121 false false R122.htm 41305 - Disclosure - Leases - ROU Assets and Lease Liabilities (Details) Sheet http://www.ibm.com/role/DisclosureLeasesRouAssetsAndLeaseLiabilitiesDetails Leases - ROU Assets and Lease Liabilities (Details) Details 122 false false R123.htm 41306 - Disclosure - Leases - Lease Amounts Included in Consolidated Income Statement (Details) Sheet http://www.ibm.com/role/DisclosureLeasesLeaseAmountsIncludedInConsolidatedIncomeStatementDetails Leases - Lease Amounts Included in Consolidated Income Statement (Details) Details 123 false false R124.htm 41307 - Disclosure - Leases - Maturity Analysis of Lease Payments Due on Sales-type and Direct Financing Leases (Details) Sheet http://www.ibm.com/role/DisclosureLeasesMaturityAnalysisOfLeasePaymentsDueOnSalesTypeAndDirectFinancingLeasesDetails Leases - Maturity Analysis of Lease Payments Due on Sales-type and Direct Financing Leases (Details) Details 124 false false R125.htm 41308 - Disclosure - Leases - Maturity Analysis of Undiscounted Lease Payments on Operating Leases (Details) Sheet http://www.ibm.com/role/DisclosureLeasesMaturityAnalysisOfUndiscountedLeasePaymentsOnOperatingLeasesDetails Leases - Maturity Analysis of Undiscounted Lease Payments on Operating Leases (Details) Details 125 false false R126.htm 41401 - Disclosure - Intangible Assets Including Goodwill - Intangible Assets by Class (Details) Sheet http://www.ibm.com/role/DisclosureIntangibleAssetsIncludingGoodwillIntangibleAssetsByClassDetails Intangible Assets Including Goodwill - Intangible Assets by Class (Details) Details 126 false false R127.htm 41402 - Disclosure - Intangible Assets Including Goodwill - Intangible Assets Activity (Details) Sheet http://www.ibm.com/role/DisclosureIntangibleAssetsIncludingGoodwillIntangibleAssetsActivityDetails Intangible Assets Including Goodwill - Intangible Assets Activity (Details) Details 127 false false R128.htm 41403 - Disclosure - Intangible Assets Including Goodwill - Future Amortization (Details) Sheet http://www.ibm.com/role/DisclosureIntangibleAssetsIncludingGoodwillFutureAmortizationDetails Intangible Assets Including Goodwill - Future Amortization (Details) Details 128 false false R129.htm 41404 - Disclosure - Intangible Assets Including Goodwill - Goodwill by Segment (Details) Sheet http://www.ibm.com/role/DisclosureIntangibleAssetsIncludingGoodwillGoodwillBySegmentDetails Intangible Assets Including Goodwill - Goodwill by Segment (Details) Details 129 false false R130.htm 41501 - Disclosure - Investments & Sundry Assets (Details) Sheet http://www.ibm.com/role/DisclosureInvestmentsSundryAssetsDetails Investments & Sundry Assets (Details) Details http://www.ibm.com/role/DisclosureInvestmentsSundryAssetsTables 130 false false R131.htm 41601 - Disclosure - Borrowings - Short-Term Debt (Details) Sheet http://www.ibm.com/role/DisclosureBorrowingsShortTermDebtDetails Borrowings - Short-Term Debt (Details) Details 131 false false R132.htm 41602 - Disclosure - Borrowings - Long-Term Debt, Components (Details) Sheet http://www.ibm.com/role/DisclosureBorrowingsLongTermDebtComponentsDetails Borrowings - Long-Term Debt, Components (Details) Details 132 false false R133.htm 41603 - Disclosure - Borrowings - Long-Term Debt, Covenants (Details) Sheet http://www.ibm.com/role/DisclosureBorrowingsLongTermDebtCovenantsDetails Borrowings - Long-Term Debt, Covenants (Details) Details 133 false false R134.htm 41604 - Disclosure - Borrowings - Long-Term Debt, Debt Issued (Details) Sheet http://www.ibm.com/role/DisclosureBorrowingsLongTermDebtDebtIssuedDetails Borrowings - Long-Term Debt, Debt Issued (Details) Details 134 false false R135.htm 41605 - Disclosure - Borrowings - Post-Swap Borrowing (Details) Sheet http://www.ibm.com/role/DisclosureBorrowingsPostSwapBorrowingDetails Borrowings - Post-Swap Borrowing (Details) Details 135 false false R136.htm 41606 - Disclosure - Borrowings - Pre-Swap Obligations (Details) Sheet http://www.ibm.com/role/DisclosureBorrowingsPreSwapObligationsDetails Borrowings - Pre-Swap Obligations (Details) Details 136 false false R137.htm 41607 - Disclosure - Borrowings - Interest on Debt (Details) Sheet http://www.ibm.com/role/DisclosureBorrowingsInterestOnDebtDetails Borrowings - Interest on Debt (Details) Details 137 false false R138.htm 41608 - Disclosure - Borrowings - Lines of Credit (Details) Sheet http://www.ibm.com/role/DisclosureBorrowingsLinesOfCreditDetails Borrowings - Lines of Credit (Details) Details 138 false false R139.htm 41701 - Disclosure - Other Liabilities - Components (Details) Sheet http://www.ibm.com/role/DisclosureOtherLiabilitiesComponentsDetails Other Liabilities - Components (Details) Details 139 false false R140.htm 41702 - Disclosure - Other Liabilities - Workforce Reduction and Environmental Liabilities (Details) Sheet http://www.ibm.com/role/DisclosureOtherLiabilitiesWorkforceReductionAndEnvironmentalLiabilitiesDetails Other Liabilities - Workforce Reduction and Environmental Liabilities (Details) Details 140 false false R141.htm 41801 - Disclosure - Commitments & Contingencies - Extensions of Credit (Details) Sheet http://www.ibm.com/role/DisclosureCommitmentsContingenciesExtensionsOfCreditDetails Commitments & Contingencies - Extensions of Credit (Details) Details 141 false false R142.htm 41802 - Disclosure - Commitments & Contingencies - Standard Warranty Liability (Details) Sheet http://www.ibm.com/role/DisclosureCommitmentsContingenciesStandardWarrantyLiabilityDetails Commitments & Contingencies - Standard Warranty Liability (Details) Details 142 false false R143.htm 41803 - Disclosure - Commitments & Contingencies - Extended Warranty Liability (Details) Sheet http://www.ibm.com/role/DisclosureCommitmentsContingenciesExtendedWarrantyLiabilityDetails Commitments & Contingencies - Extended Warranty Liability (Details) Details 143 false false R144.htm 41804 - Disclosure - Commitments & Contingencies - Contingencies (Details) Sheet http://www.ibm.com/role/DisclosureCommitmentsContingenciesContingenciesDetails Commitments & Contingencies - Contingencies (Details) Details 144 false false R145.htm 41901 - Disclosure - Equity Activity - Stock Repurchases and Other Transactions (Details) Sheet http://www.ibm.com/role/DisclosureEquityActivityStockRepurchasesAndOtherTransactionsDetails Equity Activity - Stock Repurchases and Other Transactions (Details) Details 145 false false R146.htm 41902 - Disclosure - Equity Activity - Reclassifications and Taxes (Details) Sheet http://www.ibm.com/role/DisclosureEquityActivityReclassificationsAndTaxesDetails Equity Activity - Reclassifications and Taxes (Details) Details 146 false false R147.htm 41903 - Disclosure - Equity Activity - AOCI Rollforward (Details) Sheet http://www.ibm.com/role/DisclosureEquityActivityAociRollforwardDetails Equity Activity - AOCI Rollforward (Details) Details 147 false false R148.htm 42001 - Disclosure - Derivative Financial Instruments - Offsetting (Details) Sheet http://www.ibm.com/role/DisclosureDerivativeFinancialInstrumentsOffsettingDetails Derivative Financial Instruments - Offsetting (Details) Details 148 false false R149.htm 42002 - Disclosure - Derivative Financial Instruments - Hedging Programs (Details) Sheet http://www.ibm.com/role/DisclosureDerivativeFinancialInstrumentsHedgingProgramsDetails Derivative Financial Instruments - Hedging Programs (Details) Details 149 false false R150.htm 42003 - Disclosure - Derivative Financial Instruments - Cumulative Basis Adjustments for Fair Value Hedges (Details) Sheet http://www.ibm.com/role/DisclosureDerivativeFinancialInstrumentsCumulativeBasisAdjustmentsForFairValueHedgesDetails Derivative Financial Instruments - Cumulative Basis Adjustments for Fair Value Hedges (Details) Details 150 false false R151.htm 42004 - Disclosure - Derivative Financial Instruments - Effect of Hedge Activity on Income and Expense (Details) Sheet http://www.ibm.com/role/DisclosureDerivativeFinancialInstrumentsEffectOfHedgeActivityOnIncomeAndExpenseDetails Derivative Financial Instruments - Effect of Hedge Activity on Income and Expense (Details) Details 151 false false R152.htm 42005 - Disclosure - Derivative Financial Instruments - Gains and Losses (Details) Sheet http://www.ibm.com/role/DisclosureDerivativeFinancialInstrumentsGainsAndLossesDetails Derivative Financial Instruments - Gains and Losses (Details) Details 152 false false R153.htm 42101 - Disclosure - Stock-Based Compensation (Details) Sheet http://www.ibm.com/role/DisclosureStockBasedCompensationDetails Stock-Based Compensation (Details) Details http://www.ibm.com/role/DisclosureStockBasedCompensationTables 153 false false R154.htm 42102 - Disclosure - Stock-Based Compensation - Incentive Awards (Details) Sheet http://www.ibm.com/role/DisclosureStockBasedCompensationIncentiveAwardsDetails Stock-Based Compensation - Incentive Awards (Details) Details 154 false false R155.htm 42103 - Disclosure - Stock-Based Compensation - RSU and PSU Activity (Details) Sheet http://www.ibm.com/role/DisclosureStockBasedCompensationRsuAndPsuActivityDetails Stock-Based Compensation - RSU and PSU Activity (Details) Details 155 false false R156.htm 42104 - Disclosure - Stock-Based Compensation - RSUs and PSUs, Other Disclosures (Details) Sheet http://www.ibm.com/role/DisclosureStockBasedCompensationRsusAndPsusOtherDisclosuresDetails Stock-Based Compensation - RSUs and PSUs, Other Disclosures (Details) Details 156 false false R157.htm 42105 - Disclosure - Stock-Based Compensation - Stock Option Activity (Details) Sheet http://www.ibm.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails Stock-Based Compensation - Stock Option Activity (Details) Details 157 false false R158.htm 42106 - Disclosure - Stock-Based Compensation - Acquisitions (Details) Sheet http://www.ibm.com/role/DisclosureStockBasedCompensationAcquisitionsDetails Stock-Based Compensation - Acquisitions (Details) Details 158 false false R159.htm 42107 - Disclosure - Stock-Based Compensation - ESPP (Details) Sheet http://www.ibm.com/role/DisclosureStockBasedCompensationEsppDetails Stock-Based Compensation - ESPP (Details) Details 159 false false R160.htm 42201 - Disclosure - Retirement-Related Benefits - Defined Benefit Plans (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsDefinedBenefitPlansDetails Retirement-Related Benefits - Defined Benefit Plans (Details) Details 160 false false R161.htm 42202 - Disclosure - Retirement-Related Benefits - Defined Contribution Plans (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsDefinedContributionPlansDetails Retirement-Related Benefits - Defined Contribution Plans (Details) Details 161 false false R162.htm 42203 - Disclosure - Retirement-Related Benefits - All Retirement Plans Cost (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsAllRetirementPlansCostDetails Retirement-Related Benefits - All Retirement Plans Cost (Details) Details 162 false false R163.htm 42204 - Disclosure - Retirement-Related Benefits - PBO, APBO, FV of Plan Assets, Funded Status (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsPboApboFvOfPlanAssetsFundedStatusDetails Retirement-Related Benefits - PBO, APBO, FV of Plan Assets, Funded Status (Details) Details 163 false false R164.htm 42205 - Disclosure - Retirement-Related Benefits - Net Periodic Cost (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsNetPeriodicCostDetails Retirement-Related Benefits - Net Periodic Cost (Details) Details 164 false false R165.htm 42206 - Disclosure - Retirement-Related Benefits - Changes in Benefit Obligation and Plan Assets (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsChangesInBenefitObligationAndPlanAssetsDetails Retirement-Related Benefits - Changes in Benefit Obligation and Plan Assets (Details) Details 165 false false R166.htm 42207 - Disclosure - Retirement-Related Benefits - Net Funded Status (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsNetFundedStatusDetails Retirement-Related Benefits - Net Funded Status (Details) Details 166 false false R167.htm 42208 - Disclosure - Retirement-Related Benefits - OCI and AOCI (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsOciAndAociDetails Retirement-Related Benefits - OCI and AOCI (Details) Details 167 false false R168.htm 42209 - Disclosure - Retirement-Related Benefits - Assumptions (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsAssumptionsDetails Retirement-Related Benefits - Assumptions (Details) Details 168 false false R169.htm 42210 - Disclosure - Retirement-Related Benefits - Investment Strategy (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsInvestmentStrategyDetails Retirement-Related Benefits - Investment Strategy (Details) Details 169 false false R170.htm 42211 - Disclosure - Retirement-Related Benefits - Plan Assets (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsPlanAssetsDetails Retirement-Related Benefits - Plan Assets (Details) Details 170 false false R171.htm 42212 - Disclosure - Retirement-Related Benefits - Level 3 Reconciliation (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsLevel3ReconciliationDetails Retirement-Related Benefits - Level 3 Reconciliation (Details) Details 171 false false R172.htm 42213 - Disclosure - Retirement-Related Benefits - Contributions and Direct Benefit Payments (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsContributionsAndDirectBenefitPaymentsDetails Retirement-Related Benefits - Contributions and Direct Benefit Payments (Details) Details 172 false false R173.htm 42214 - Disclosure - Retirement-Related Benefits - Contributions, Defined Benefit Pension Plans (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsContributionsDefinedBenefitPensionPlansDetails Retirement-Related Benefits - Contributions, Defined Benefit Pension Plans (Details) Details 173 false false R174.htm 42216 - Disclosure - Retirement-Related Benefits - Expected Benefit Payments (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsExpectedBenefitPaymentsDetails Retirement-Related Benefits - Expected Benefit Payments (Details) Details 174 false false R175.htm 42217 - Disclosure - Retirement-Related Benefits - ABO and APBO in Excess of Plan Assets (Details) Sheet http://www.ibm.com/role/DisclosureRetirementRelatedBenefitsAboAndApboInExcessOfPlanAssetsDetails Retirement-Related Benefits - ABO and APBO in Excess of Plan Assets (Details) Details 175 false false R176.htm 42301 - Disclosure - Subsequent Events (Details) Sheet http://www.ibm.com/role/DisclosureSubsequentEventsDetails Subsequent Events (Details) Details http://www.ibm.com/role/DisclosureSubsequentEvents 176 false false R177.htm 42401 - Disclosure - SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (Details) Sheet http://www.ibm.com/role/DisclosureScheduleIiValuationAndQualifyingAccountsAndReservesDetails SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (Details) Details http://www.ibm.com/role/DisclosureScheduleIiValuationAndQualifyingAccountsAndReserves 177 false false All Reports Book All Reports ibm-20201231x10k.htm ibm-20201231xex13.htm ibm-20201231.xsd ibm-20201231_cal.xml ibm-20201231_def.xml ibm-20201231_lab.xml ibm-20201231_pre.xml ibm-20201231xex10d1.htm ibm-20201231xex10d2.htm ibm-20201231xex10d3.htm ibm-20201231xex10d4.htm ibm-20201231xex21.htm ibm-20201231xex23d1.htm ibm-20201231xex24d1.htm ibm-20201231xex24d2.htm ibm-20201231xex31d1.htm ibm-20201231xex31d2.htm ibm-20201231xex32d1.htm ibm-20201231xex32d2.htm ibm-20201231xex3d2.htm ibm-20201231xex4d1.htm ibm-20201231xex13001.jpg ibm-20201231xex13002.jpg http://xbrl.sec.gov/currency/2020-01-31 http://fasb.org/srt/2020-01-31 http://xbrl.sec.gov/exch/2020-01-31 http://fasb.org/us-gaap/2020-01-31 http://xbrl.sec.gov/dei/2020-01-31 http://xbrl.sec.gov/country/2020-01-31 true true