XML 48 R109.htm IDEA: XBRL DOCUMENT v2.4.1.9
Retirement-Related Benefits (Net Periodic Income Cost) (Details 2) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Retirement-related Benefits Disclosures      
Total defined contribution plans cost $ 1,253us-gaap_DefinedContributionPlanCostRecognized $ 1,384us-gaap_DefinedContributionPlanCostRecognized $ 1,506us-gaap_DefinedContributionPlanCostRecognized
Total retirement-related benefits net periodic cost 1,974us-gaap_PensionAndOtherPostretirementBenefitExpense 2,876us-gaap_PensionAndOtherPostretirementBenefitExpense 2,389us-gaap_PensionAndOtherPostretirementBenefitExpense
Defined Benefit Pension Plans      
Retirement-related Benefits Disclosures      
Total defined benefit pension plans (income)/cost 449us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember		 1,195us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember		 533us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
U.S. Defined Benefit Pension Plans      
Retirement-related Benefits Disclosures      
Total defined benefit pension plans (income)/cost (818)us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember		 (202)us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember		 (507)us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
Personal Pension Plan (PPP)      
Retirement-related Benefits Disclosures      
Total defined benefit pension plans (income)/cost (833)us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_PersonalPensionPlanMember		 (223)us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_PersonalPensionPlanMember		 (526)us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_PersonalPensionPlanMember
Retention Plan      
Retirement-related Benefits Disclosures      
Total defined benefit pension plans (income)/cost 15us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_UnitedStatesSupplementalExecutiveRetentionPlanDefinedBenefitMember		 21us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_UnitedStatesSupplementalExecutiveRetentionPlanDefinedBenefitMember		 18us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_UnitedStatesSupplementalExecutiveRetentionPlanDefinedBenefitMember
Non-U.S. Defined Benefit Pension Plans      
Retirement-related Benefits Disclosures      
Total defined benefit pension plans (income)/cost 1,267us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember		 1,396us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember		 1,040us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_ForeignPensionPlansDefinedBenefitMember
PPP and Non-U.S. Defined Benefit Pension Plans      
Retirement-related Benefits Disclosures      
Total defined benefit pension plans (income)/cost 434us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_PersonalPensionPlanAndForeignDefinedBenefitPensionPlanMember		 1,173us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_PersonalPensionPlanAndForeignDefinedBenefitPensionPlanMember		 515us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_PersonalPensionPlanAndForeignDefinedBenefitPensionPlanMember
U.S. Defined Contribution Plans      
Retirement-related Benefits Disclosures      
Total defined contribution plans cost 727us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_UnitedStatesPensionPlanOfUsEntityDefinedContributionMember		 809us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_UnitedStatesPensionPlanOfUsEntityDefinedContributionMember		 885us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_UnitedStatesPensionPlanOfUsEntityDefinedContributionMember
IBM 401(k) Plus Plan      
Retirement-related Benefits Disclosures      
Total defined contribution plans cost 713us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_IBM401kPlusPlanMember		 785us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_IBM401kPlusPlanMember		 857us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_IBM401kPlusPlanMember
IBM Excess 401(k) Plus Plan      
Retirement-related Benefits Disclosures      
Total defined contribution plans cost 14us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_IBMExcess401kPlusPlanMember		 24us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_IBMExcess401kPlusPlanMember		 29us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_IBMExcess401kPlusPlanMember
Non-U.S. Defined Contribution Plans      
Retirement-related Benefits Disclosures      
Total defined contribution plans cost 526us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_ForeignPensionPlanDefinedContributionMember		 575us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_ForeignPensionPlanDefinedContributionMember		 621us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_ForeignPensionPlanDefinedContributionMember
IBM 401(k) Plus Plan and Non-U.S. Defined Contribution Plans      
Retirement-related Benefits Disclosures      
Total defined contribution plans cost 1,239us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_Ibm401kPlusPlanAndForeignDefinedContributionPlanMember		 1,361us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_Ibm401kPlusPlanAndForeignDefinedContributionPlanMember		 1,478us-gaap_DefinedContributionPlanCostRecognized
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_Ibm401kPlusPlanAndForeignDefinedContributionPlanMember
Nonpension Postretirement Plans      
Retirement-related Benefits Disclosures      
Total defined benefit pension plans (income)/cost 272us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember		 298us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember		 350us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
U.S. Nonpension Postretirement Benefit Plans      
Retirement-related Benefits Disclosures      
Total defined benefit pension plans (income)/cost 206us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMember		 218us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMember		 268us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMember
Non-U.S. Nonpension Postretirement Plans      
Retirement-related Benefits Disclosures      
Total defined benefit pension plans (income)/cost 66us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_ForeignPostretirementBenefitPlansDefinedBenefitMember		 79us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_ForeignPostretirementBenefitPlansDefinedBenefitMember		 82us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
/ ibm_RetirementRelatedBenefitPlansAxis
= us-gaap_ForeignPostretirementBenefitPlansDefinedBenefitMember
U.S. Plans      
Retirement-related Benefits Disclosures      
Total retirement-related benefits net periodic cost 115us-gaap_PensionAndOtherPostretirementBenefitExpense
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_UnitedStatesRetirementRelatedBenefitPlansMember		 826us-gaap_PensionAndOtherPostretirementBenefitExpense
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_UnitedStatesRetirementRelatedBenefitPlansMember		 646us-gaap_PensionAndOtherPostretirementBenefitExpense
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_UnitedStatesRetirementRelatedBenefitPlansMember
Non-U.S. Plans      
Retirement-related Benefits Disclosures      
Total retirement-related benefits net periodic cost $ 1,859us-gaap_PensionAndOtherPostretirementBenefitExpense
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_ForeignRetirementRelatedBenefitPlansMember		 $ 2,051us-gaap_PensionAndOtherPostretirementBenefitExpense
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_ForeignRetirementRelatedBenefitPlansMember		 $ 1,743us-gaap_PensionAndOtherPostretirementBenefitExpense
/ ibm_RetirementRelatedBenefitPlansAxis
= ibm_ForeignRetirementRelatedBenefitPlansMember