The percent of goodwill arising from a business combination that is expected to be deductible for tax purposes.

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Amount of consideration transferred, consisting of settlement of pre-existing relationships.

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Amount of cost and expense not yet recognized for employee cash compensation not yet earned under employee retention plans.

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Period over which cost and expense not yet recognized for cash payout is expected to be recognized for employee retention plan, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of amortization expense attributable to debt issuance costs.

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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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This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

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This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

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Amount of expense for employee benefit and equity-based compensation.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Acquisitions & Divestitures - Businesses Acquired, 2019, Goodwill and Compensation Expense (Details) - USD ($) $ in Millions		6 Months Ended	12 Months Ended
	Jul. 09, 2019	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Acquisitions
Goodwill		$ 58,222	$ 58,222	$ 36,265	$ 36,788
Red Hat, Inc.
Acquisitions
Acquired intangible asset, weighted average useful life	10 years 10 months 24 days
Goodwill	$ 23,125	23,100	$ 23,100
Expected percent of goodwill deductible for tax purposes			7.00%
Compensation expense		230
Remaining compensation expense		185	$ 185
Settlement of pre-existing relationships	$ 60
Revenue since date of acquisition		945
Pre-tax income since date of acquisition		(1,658)
Red Hat, Inc. \| Cost of sales
Acquisitions
Compensation expense		20
Red Hat, Inc. \| SG&A expense
Acquisitions
Acquisition costs			$ 189
Compensation expense		124
Red Hat, Inc. \| Research, development and engineering
Acquisitions
Compensation expense		86
Red Hat, Inc. \| Maximum
Acquisitions
Remaining compensation expense recognition period			3 years
Red Hat, Inc. \| Minimum
Acquisitions
Remaining compensation expense recognition period			6 months
Red Hat, Inc. \| 364-Day Bridge Facility \| SG&A expense
Acquisitions
Amortized costs			$ 55
Cloud & Cognitive Software \| Red Hat, Inc.
Acquisitions
Goodwill		18,500	18,500
Global Technology Services \| Red Hat, Inc.
Acquisitions
Goodwill		3,100	3,100
Global Business Services \| Red Hat, Inc.
Acquisitions
Goodwill		1,100	1,100
Systems \| Red Hat, Inc.
Acquisitions
Goodwill		$ 400	$ 400