Exit and disposal activities - Restructuring Reserve Activity (Details) $ in Millions	3 Months Ended
Nov. 30, 2019 USD ($)
Transformational Cost Management Program
Restructuring Reserve [Roll Forward]
Beginning balance	$ 78
Costs	64
Payments	(27)
Other - non cash	(14)
Currency translation adjustments	1
ASC 842 Leases adoption	(4)
Ending balance	98
Store Optimization Program
Restructuring Reserve [Roll Forward]
Beginning balance	429
Costs	9
Payments	(35)
ASC 842 Leases adoption	(378)
Ending balance	24
Lease obligations and other real estate costs \| Transformational Cost Management Program
Restructuring Reserve [Roll Forward]
Beginning balance	17
Costs	1
Payments	(1)
Other - non cash	0
Currency translation adjustments	1
ASC 842 Leases adoption	(4)
Ending balance	14
Lease obligations and other real estate costs \| Store Optimization Program
Restructuring Reserve [Roll Forward]
Beginning balance	407
Costs	3
Payments	(9)
ASC 842 Leases adoption	(378)
Ending balance	23
Asset impairment \| Transformational Cost Management Program
Restructuring Reserve [Roll Forward]
Beginning balance	0
Costs	11
Payments	0
Other - non cash	(11)
Currency translation adjustments	0
ASC 842 Leases adoption	0
Ending balance	0
Employee severance and business transition costs \| Transformational Cost Management Program
Restructuring Reserve [Roll Forward]
Beginning balance	57
Costs	40
Payments	(22)
Other - non cash	0
Currency translation adjustments	0
ASC 842 Leases adoption	0
Ending balance	75
Information technology transformation and other exit costs \| Transformational Cost Management Program
Restructuring Reserve [Roll Forward]
Beginning balance	4
Costs	12
Payments	(4)
Other - non cash	(2)
Currency translation adjustments	0
ASC 842 Leases adoption	0
Ending balance	9
Employee severance and other exit costs \| Store Optimization Program
Restructuring Reserve [Roll Forward]
Beginning balance	22
Costs	6
Payments	(26)
ASC 842 Leases adoption	0
Ending balance	$ 1

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
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-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3367-108585

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- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
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- Definition

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

+ References

No definition available.

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- Definition

Amount of foreign currency translation gain (loss) which decreases (increases) the restructuring reserve.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
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- Definition

Restructuring Reserve, Accounting Pronouncement Adjustments

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- Definition

Restructuring Reserve, Other, Non-Cash

+ References

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