Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.

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Area code of city

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No definition available.

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End date of current fiscal year in the format --MM-DD.

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No definition available.

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Boolean flag that is true only for a form used as an annual report.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
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-Section 310

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Form 40-F
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No definition available.

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No definition available.

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- 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.

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No definition available.

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The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is YYYY-MM-DD.

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No definition available.

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Boolean flag that is true only for a form used as a transition report.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
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The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

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No definition available.

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Address Line 1 such as Attn, Building Name, Street Name

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No definition available.

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Name of the City or Town

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Code for the postal or zip code

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Name of the state or province.

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No definition available.

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A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
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Indicate number of shares or other units outstanding of each of registrant's classes of capital or common stock or other ownership interests, if and as stated on cover of related periodic report. Where multiple classes or units exist define each class/interest by adding class of stock items such as Common Class A [Member], Common Class B [Member] or Partnership Interest [Member] onto the Instrument [Domain] of the Entity Listings, Instrument.

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No definition available.

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Indicate 'Yes' or 'No' whether registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that registrants were required to file such reports), and (2) have been subject to such filing requirements for the past 90 days. This information should be based on the registrant's current or most recent filing containing the related disclosure.

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No definition available.

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- Definition

Indicate if registrant meets the emerging growth company criteria.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation 12B
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-Section 12
-Subsection b-2

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- Definition

Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

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No definition available.

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- Definition

Indicate whether the registrant is one of the following: Large Accelerated Filer, Accelerated Filer, Non-accelerated Filer. Definitions of these categories are stated in Rule 12b-2 of the Exchange Act. This information should be based on the registrant's current or most recent filing containing the related disclosure.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation 12B
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- Definition

Two-character EDGAR code representing the state or country of incorporation.

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No definition available.

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Boolean flag that is true when the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
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The aggregate market value of the voting and non-voting common equity held by non-affiliates computed by reference to the price at which the common equity was last sold, or the average bid and asked price of such common equity, as of the last business day of the registrant's most recently completed second fiscal quarter.

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No definition available.

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- Definition

The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation 12B
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- Definition

Boolean flag that is true when the registrant is a shell company as defined in Rule 12b-2 of the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation 12B
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Indicates that the company is a Smaller Reporting Company (SRC).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation 12B
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- Definition

The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation 12B
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Indicate 'Yes' or 'No' if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.

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No definition available.

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Indicate 'Yes' or 'No' if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Is used on Form Type: 10-K, 10-Q, 8-K, 20-F, 6-K, 10-K/A, 10-Q/A, 20-F/A, 6-K/A, N-CSR, N-Q, N-1A.

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No definition available.

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- Definition

Local phone number for entity.

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No definition available.

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- Definition

Title of a 12(b) registered security.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
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-Section 12
-Subsection b

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- Definition

Name of the Exchange on which a security is registered.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 12
-Subsection d1-1

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- Definition

Trading symbol of an instrument as listed on an exchange.

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No definition available.

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Document and Entity Information - USD ($) $ in Billions	12 Months Ended
Document and Entity Information - USD ($) $ in Billions	Dec. 31, 2020	Feb. 10, 2021	Jun. 30, 2020
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2020
Entity File Number	1-2360
Entity Registrant Name	INTERNATIONAL BUSINESS MACHINES CORPORATION
Entity Incorporation, State or Country Code	NY
Entity Tax Identification Number	13-0871985
Entity Address, Address Line One	One New Orchard Road
Entity Address, City or Town	Armonk
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10504
City Area Code	914
Local Phone Number	499-1900
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Central Index Key	0000051143
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		893,594,090
Entity Public Float			$ 107.5
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
New York Stock Exchange \| Common Stock
Document Information [Line Items]
Title of 12(b) Security	Capital stock, par value $.20 per share
Trading Symbol	IBM
Security Exchange Name	NYSE
New York Stock Exchange \| 0.500% Notes due 2021
Document Information [Line Items]
Title of 12(b) Security	0.500% Notes due 2021
Trading Symbol	IBM 21B
Security Exchange Name	NYSE
New York Stock Exchange \| 2.625% Notes due 2022
Document Information [Line Items]
Title of 12(b) Security	2.625% Notes due 2022
Trading Symbol	IBM 22A
Security Exchange Name	NYSE
New York Stock Exchange \| 1.250% Notes due 2023
Document Information [Line Items]
Title of 12(b) Security	1.250% Notes due 2023
Trading Symbol	IBM 23A
Security Exchange Name	NYSE
New York Stock Exchange \| 0.375% Notes due 2023
Document Information [Line Items]
Title of 12(b) Security	0.375% Notes due 2023
Trading Symbol	IBM 23B
Security Exchange Name	NYSE
New York Stock Exchange \| 1.125% Notes due 2024
Document Information [Line Items]
Title of 12(b) Security	1.125% Notes due 2024
Trading Symbol	IBM 24A
Security Exchange Name	NYSE
New York Stock Exchange \| 2.875% Notes due 2025
Document Information [Line Items]
Title of 12(b) Security	2.875% Notes due 2025
Trading Symbol	IBM 25A
Security Exchange Name	NYSE
New York Stock Exchange \| 0.950% Notes due 2025
Document Information [Line Items]
Title of 12(b) Security	0.950% Notes due 2025
Trading Symbol	IBM 25B
Security Exchange Name	NYSE
New York Stock Exchange \| 0.875% Notes due 2025
Document Information [Line Items]
Title of 12(b) Security	0.875% Notes due 2025
Trading Symbol	IBM 25C
Security Exchange Name	NYSE
New York Stock Exchange \| 0.300% Notes due 2026
Document Information [Line Items]
Title of 12(b) Security	0.300% Notes due 2026
Trading Symbol	IBM 26B
Security Exchange Name	NYSE
New York Stock Exchange \| 1.250% Notes due 2027
Document Information [Line Items]
Title of 12(b) Security	1.250% Notes due 2027
Trading Symbol	IBM 27B
Security Exchange Name	NYSE
New York Stock Exchange \| 0.300% Notes due 2028
Document Information [Line Items]
Title of 12(b) Security	0.300% Notes due 2028
Trading Symbol	IBM 28B
Security Exchange Name	NYSE
New York Stock Exchange \| 1.750% Notes due 2028
Document Information [Line Items]
Title of 12(b) Security	1.750% Notes due 2028
Trading Symbol	IBM 28A
Security Exchange Name	NYSE
New York Stock Exchange \| 1.500% Notes due 2029
Document Information [Line Items]
Title of 12(b) Security	1.500% Notes due 2029
Trading Symbol	IBM 29
Security Exchange Name	NYSE
New York Stock Exchange \| 1.750% Notes due 2031
Document Information [Line Items]
Title of 12(b) Security	1.750% Notes due 2031
Trading Symbol	IBM 31
Security Exchange Name	NYSE
New York Stock Exchange \| 0.650% Notes due 2032
Document Information [Line Items]
Title of 12(b) Security	0.650% Notes due 2032
Trading Symbol	IBM 32A
Security Exchange Name	NYSE
New York Stock Exchange \| 1.200% Notes due 2040
Document Information [Line Items]
Title of 12(b) Security	1.200% Notes due 2040
Trading Symbol	IBM 40
Security Exchange Name	NYSE
New York Stock Exchange \| 7.00% Debentures due 2025
Document Information [Line Items]
Title of 12(b) Security	7.00% Debentures due 2025
Trading Symbol	IBM 25
Security Exchange Name	NYSE
New York Stock Exchange \| 6.22% Debentures due 2027
Document Information [Line Items]
Title of 12(b) Security	6.22% Debentures due 2027
Trading Symbol	IBM 27
Security Exchange Name	NYSE
New York Stock Exchange \| 6.50% Debentures due 2028
Document Information [Line Items]
Title of 12(b) Security	6.50% Debentures due 2028
Trading Symbol	IBM 28
Security Exchange Name	NYSE
New York Stock Exchange \| 7.00% Debentures due 2045
Document Information [Line Items]
Title of 12(b) Security	7.00% Debentures due 2045
Trading Symbol	IBM 45
Security Exchange Name	NYSE
New York Stock Exchange \| 7.125% Debentures due 2096
Document Information [Line Items]
Title of 12(b) Security	7.125% Debentures due 2096
Trading Symbol	IBM 96
Security Exchange Name	NYSE
Chicago Stock Exchange \| Common Stock
Document Information [Line Items]
Title of 12(b) Security	Capital stock, par value $.20 per share
Trading Symbol	IBM
Security Exchange Name	CHX