XML 32 R23.htm IDEA: XBRL DOCUMENT
v3.21.1

Equity (Tables) | 8 Months Ended
--- | ---
May 09, 2021
Equity [Abstract] |
Stock Repurchased During Period | Stock repurchase activity during the third quarter and first thirty-six weeks of 2021 and 2020 is summarized below:
| Shares Repurchased (000s) |  | Average Price per Share |  | Total Cost
Third quarter of 2021 | 519 |  |  | $ | 346.19 |  |  | $ | 179 |
First thirty-six weeks of 2021 | 1,040 |  |  | $ | 353.87 |  |  | $ | 368 |
Third quarter of 2020 | 106 |  |  | $ | 296.38 |  |  | $ | 31 |
First thirty-six weeks of 2020 | 368 |  |  | $ | 298.53 |  |  | $ | 110 |

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

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