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This element represent a number of business segments to which landlord ownership is assigned to when assets are shared between several segments.

No definition available.

Name:	ibm_NumberOfBusinessSegmentsToWhichLandlordOwnershipIsAssignedToWhenAssetsAreShared
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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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Amount of the cost of borrowed funds accounted for as interest expense.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

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Balance Type:	credit
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Name:	srt_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
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Balance Type:
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Name:	us-gaap_StatementBusinessSegmentsAxis=ibm_CognitiveSolutionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementBusinessSegmentsAxis=ibm_GlobalBusinessServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementBusinessSegmentsAxis=ibm_TechnologyServicesCloudPlatformsMember
Namespace Prefix:
Data Type:	na
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Period Type:

Name:	us-gaap_StatementBusinessSegmentsAxis=ibm_SystemsMember
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Data Type:	na
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