Represents the number of divestitures completed during the period.

No definition available.

Name:	ibm_BusinessDivestituresNumberOfDivestituresCompleted
Namespace Prefix:	ibm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of noncash proceeds received resulting from the sale of a business component and recorded as a note receivable.

+ References

No definition available.

+ Details

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

- Definition

This element represents the number of steps and/or phases in the process to dispose of an asset group that has been completed.

+ References

No definition available.

+ Details

Name:	ibm_DisposalGroupNotDiscontinuedOperationsPhasesOfTransactionCompleted
Namespace Prefix:	ibm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the consideration to be received, net of closing date working capital adjustments, for the sale of a business that is not a discontinued operation.

+ References

No definition available.

+ Details

Name:	ibm_DisposalGroupNotDiscontinuedOperationsTransactionPrice
Namespace Prefix:	ibm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow associated with the amount to be received at the closing date from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

No definition available.

+ Details

Name:	ibm_ProceedsToBeReceivedFromDivestitureOfBusinesses
Namespace Prefix:	ibm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_BusinessCombinationsAbstract
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The gain (loss) resulting from the sale of a disposal group that is not a discontinued operation. It is included in income from continuing operations before income taxes in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 144

-Paragraph 37, 45

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1361-107760

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 144

-Paragraph 47

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2443-110228

+ Details

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

- Definition

This element represents the cash inflow during the period from the sale of a component of the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3179-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 15, 16

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_SignificantAcquisitionsAndDisposalsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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Period Type:	duration

Acquisitions/Divestitures (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended			0 Months Ended	12 Months Ended		3 Months Ended
	Jun. 30, 2011 item	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Apr. 17, 2012 Retail Stores Solutions business	Dec. 31, 2012 Retail Stores Solutions business item	Dec. 31, 2012 Retail Stores Solutions business Total Estimated	Mar. 31, 2010 Dassault Systems
Acquisitions/Divestitures
Number of divestitures	2
Divestitures:
Phases of sale completed						3
Proceeds from sale of business		$ 599	$ 14	$ 55		$ 546		$ 459
Note receivable on sale of business						251
Pre-tax gain on sale of business						446	500	591
Transaction price for sale of business					850
Approximate amount of transaction price received in cash					$ 800