Amount of financing receivable transferred and uncollected.

No definition available.

Name:	ibm_FinancingReceivableTransferredAndUncollected
Namespace Prefix:	ibm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Financing Receivable, Transferred, Net Gain (Loss)

+ References

No definition available.

+ Details

Name:	ibm_FinancingReceivableTransferredNetGainLoss
Namespace Prefix:	ibm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the amount of financing receivables to be sold in an agreement. The financing receivables may be sold at any one time, on a revolving basis.

+ References

No definition available.

+ Details

Name:	ibm_FinancingReceivablesToBeSold
Namespace Prefix:	ibm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Transfers And Servicing Of Financial Assets, Sales Agreement Period

+ References

No definition available.

+ Details

Name:	ibm_TransfersAndServicingOfFinancialAssetsSalesAgreementPeriod
Namespace Prefix:	ibm_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of decrease in financing receivable from sale and reclassification to held-for-sale. Excludes net investment in lease.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11B
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-11B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-11

+ Details

Name:	us-gaap_FinancingReceivableSignificantSales
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=ibm_ThirdPartyInvestorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
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Financing Receivables - Transfer of Financing Assets (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Jan. 01, 2025
Financing receivables
Financing receivable transferred, net gain (loss)	$ (35)	$ (49)
Commercial Financing Receivables
Financing receivables
Financing receivables transferred	5,681	5,590
Financing receivables transferred and uncollected	$ 712	$ 691
Commercial Financing Receivables \| Third Party Investor
Financing receivables
Transfer of financial assets, sales period			26 months
Commercial Financing Receivables \| Third Party Investor \| Maximum
Financing receivables
Financing receivables to be sold			$ 1,300