Goodwill and other intangible assets - Schedule of Goodwill (Details) $ in Millions	6 Months Ended
Feb. 28, 2021 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 12,013
Acquisitions	406
Currency translation adjustments	51
Goodwill, ending balance	12,468
Reportable Segments \| United States
Goodwill [Roll Forward]
Goodwill, beginning balance	10,553
Acquisitions	394
Currency translation adjustments	0
Goodwill, ending balance	10,947
Reportable Segments \| International
Goodwill [Roll Forward]
Goodwill, beginning balance	1,460
Acquisitions	12
Currency translation adjustments	51
Goodwill, ending balance	$ 1,521

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(10)(1))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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