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Represents a number of years ago an outdated pension plan was elected to forego by employees.

+ References

No definition available.

+ Details

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- Definition

Represents the period for which reports need to be submitted to Securities Exchange Commission and court on certain matters, including those relating to compliance with the Foreign Corrupt Practices Act of 1977.

+ References

No definition available.

+ Details

Name:	ibm_LossContingencyPeriodForWhichReportsAreToBeSubmittedToSecuritiesExchangeCommissionAndCourt
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- Definition

Amount of judgment or settlement awarded to (against) the entity in respect of litigation.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Details

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- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 9

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349

+ Details

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

- Definition

Number of defendants named in a legal action.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of pending claims pertaining to a loss contingency.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of countries in which the entity operates as of balance sheet date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
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Period Type:	instant

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- Details

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- Details

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- Details

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- Details

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- Details

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Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	0 Months Ended
	Mar. 31, 2015	Jul. 25, 2013	Feb. 13, 2014	Jul. 18, 2012
Contingencies:
Clients presence in number of countries	175
Foreign Tax Authority \| Brazil
Loss Contingencies
Income tax examination - Brazil, total potential liability	525
Litigation in Spain regarding defined benefit and defined contribution plans \| Spain
Loss Contingencies
Number of years an outdated pension plan was elected to forego by employees	20 years
Litigation Case In United States District Court regarding divesting Microelectronics business
Loss Contingencies
Number of defendants	3
Former IBM UK Defined Benefit Plan Participants \| IBM United Kingdom Limited
Loss Contingencies
Claims pending	290
Civil enforcement action with the SEC
Loss Contingencies
Period for which reports are to be submitted to SEC and court on certain matters, including those relating to compliance with the FCPA		2 years
State of Indiana \| Pending Litigation
Loss Contingencies
Amount of settlement to be (paid)/received			$ 50	$ 52