The aggregated revenue from financial services, including lease and loan or working capital financing arrangements, which is excluded from the scope of ASC 606.

No definition available.

+ Details

Name:	ibm_RevenueFinancialServices
Namespace Prefix:	ibm_
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_DisaggregationOfRevenueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

+ Details

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

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(1))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

+ Details

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

Revenue Recognition - Disaggregation of Revenue by Major Products/Service Offerings (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Revenue by Major Products/Service Offerings
Total Revenue	$ 17,571	$ 18,182	$ 77,000
External Revenue
Revenue by Major Products/Service Offerings
Total Revenue	17,508	17,731
Other
Revenue by Major Products/Service Offerings
Revenue	62	451
Cloud & Cognitive Software \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	5,238	4,967
Total Revenue	5,238	4,967
Global Business Services \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	4,136	4,155
Total Revenue	4,136	4,155
Global Technology Services \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	6,467	6,875
Total Revenue	6,467	6,875
Systems \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	1,368	1,328
Total Revenue	1,368	1,328
Global Financing \| External Revenue
Revenue by Major Products/Service Offerings
Financial Services Revenue	299	406
Total Revenue	299	406
Cognitive Applications \| Cloud & Cognitive Software \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	1,182	1,238
Cloud & Data Platforms \| Cloud & Cognitive Software \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	2,536	1,917
Transaction Processing Platforms \| Cloud & Cognitive Software \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	1,520	1,812
Consulting \| Global Business Services \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	2,071	2,001
Application Management \| Global Business Services \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	1,840	1,908
Global Process Services \| Global Business Services \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	225	247
Infrastructure & Cloud Services \| Global Technology Services \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	4,916	5,209
Technology Support Services \| Global Technology Services \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	1,550	1,665
Systems Hardware \| Systems \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	997	914
Operating Systems Software \| Systems \| External Revenue
Revenue by Major Products/Service Offerings
Revenue	$ 371	$ 414