v2.4.1.9
Document and Entity Information
6 Months Ended
Feb. 15, 2015
Mar. 04, 2015
Document and Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Feb. 15, 2015  
Document Fiscal Year Focus 2015  
Document Fiscal Period Focus Q2  
Trading Symbol COST  
Entity Registrant Name COSTCO WHOLESALE CORP /NEW  
Entity Central Index Key 0000909832  
Current Fiscal Year End Date --08-30  
Entity Current Reporting Status Yes  
Entity Filer Category Large Accelerated Filer  
Entity Common Stock, Shares Outstanding   439,974,264dei_EntityCommonStockSharesOutstanding