XML 53 R41.htm IDEA: XBRL DOCUMENT
v3.23.3

Accounting Policies - Stock-Based Compensation (Details) | 12 Months Ended
--- | ---
Sep. 03, 2023
Employees [Member] |
Summary Of Significant Accounting Policies [Line Items] |
Share-based compensation arrangement by share-based payment award, award vesting period | 5 years
Share-based compensation arrangement by share-based payment number of years of service | 25 years
Non Employee Directors [Member] |
Summary Of Significant Accounting Policies [Line Items] |
Share-based compensation arrangement by share-based payment award, award vesting period | 3 years
Share-based compensation arrangement by share-based payment number of years of service | 5 years

X
- Definition The number of years of service completed by an employee with the Company at which accelerated vesting occurs. + References No definition available. + Details
Name: | cost_ShareBasedCompensationArrangementByShareBasedPaymentNumberOfYearsOfService
Namespace Prefix: | cost_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Summary Of Significant Accounting Policies [Line Items] + References No definition available. + Details
Name: | cost_SummaryOfSignificantAccountingPoliciesLineItems
Namespace Prefix: | cost_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_TitleOfIndividualAxis=cost_EmployeesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_TitleOfIndividualAxis=cost_NonEmployeeDirectorsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |