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Equity (Tables) | 3 Months Ended
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Nov. 21, 2021
Equity [Abstract] |
Stock Repurchased During Period | Stock repurchase activity during the first quarter of 2022 and 2021 is summarized below:
| Shares Repurchased (000s) |  | Average Price per Share |  | Total Cost
First quarter of 2022 | 77 |  |  | $ | 455.08 |  |  | $ | 35 |
First quarter of 2021 | 213 |  |  | $ | 359.45 |  |  | $ | 77 |

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- Definition Schedule of Common Stock Repurchased And Average Price Paid Per Share [Table Text Block] + References No definition available. + Details
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Namespace Prefix: | cost_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

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- References No definition available. + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration