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The cash inflow associated with the amount received from contingent consideration during the period.

No definition available.

Name:	ibm_DisposalGroupIncludingDiscontinuedOperationConsiderationReceived
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Data Type:	xbrli:monetaryItemType
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Amount of contingent consideration included in the total relating to the disposal of assets and liabilities.

No definition available.

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Namespace Prefix:	ibm_
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Period of time in which the company expects to receive outstanding contingent consideration.

No definition available.

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Namespace Prefix:	ibm_
Data Type:	xbrli:durationItemType
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Period after closing for receipt of the remaining cash consideration from the sale of a portion of the company's business.

No definition available.

Name:	ibm_DisposalGroupIncludingDiscontinuedOperationPeriodForReceiptOfRemainingConsideration
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Data Type:	xbrli:durationItemType
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The cash outflow on payments relating to deferred revenue that existed prior to closing of divestiture.

No definition available.

Name:	ibm_PaymentsRelatingToDeferredRevenueExistedPriorToDivestiture
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Data Type:	xbrli:monetaryItemType
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The portion of total cash payment received against receivables previously transferred as participating interest to a third-party.

No definition available.

Name:	ibm_ProceedsFromDivestiturePreviouslyTransferredAsParticipatingInterest
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Data Type:	xbrli:monetaryItemType
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Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2443-110228

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230

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Data Type:	xbrli:monetaryItemType
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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.

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Data Type:	xbrli:stringItemType
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The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3179-108585

Name:	us-gaap_ProceedsFromDivestitureOfBusinesses
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Data Type:	xbrli:monetaryItemType
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Name:	srt_StatementGeographicalAxis=country_US
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