Changes in Equity Attributes to Costco and the Noncontrolling Interests of Consolidated Subsidiaries (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Feb. 16, 2014	Feb. 17, 2013	Nov. 25, 2012	Feb. 16, 2014	Feb. 17, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity at beginning of period			$ 12,518	$ 11,012	$ 12,518
Comprehensive income:
Net income	473	554		904	975
Net Income (Loss) Attributable to Parent	463	547		888	963
Net Income (Loss) Attributable to Noncontrolling Interest	10	7		16	12
Foreign-currency translation adjustment and other, net	(120)	(65)		(36)	(43)
COMPREHENSIVE INCOME ATTRIBUTABLE TO COSTCO	347	485		853	918
Comprehensive income	353	489		868	932
Comprehensive (Income) Loss, Net of Tax, Attributable to Noncontrolling Interest	6	4		15	14
Stock-based compensation				185	159
Stock options exercised, including tax effects				18	51
Release of vested restricted stock units (RSUs), including tax effects				(101)	(83)
Conversion of convertible notes					29
Repurchases of common stock			(34)		(34)
Cash dividends declared				(273)	(3,289)
Equity at end of period	11,709	10,283		11,709	10,283
Attributable to Costco
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity at beginning of period			12,361	10,833	12,361
Comprehensive income:
Net Income (Loss) Attributable to Parent				888	963
Foreign-currency translation adjustment and other, net				(35)	(45)
Stock-based compensation				185	159
Stock options exercised, including tax effects				18	51
Release of vested restricted stock units (RSUs), including tax effects				(101)	(83)
Conversion of convertible notes					29
Repurchases of common stock					(34)
Cash dividends declared				(273)	(3,289)
Equity at end of period	11,515	10,112		11,515	10,112
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity at beginning of period			157	179	157
Comprehensive income:
Net Income (Loss) Attributable to Noncontrolling Interest				16	12
Foreign-currency translation adjustment and other, net				(1)	2
Equity at end of period	$ 194	$ 171		$ 194	$ 171