CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013
Revenues:
Net warehouse club sales	$ 657,167	$ 591,855	$ 1,246,861	$ 1,115,454
Export sales	6,764	6,323	12,485	9,396
Membership income	9,481	8,326	18,749	15,999
Other income	962	906	1,880	1,847
Total revenues	674,374	607,410	1,279,975	1,142,696
Cost of goods sold:
Net warehouse club	561,652	504,725	1,065,939	949,669
Export	6,423	5,986	11,864	8,821
Selling, general and administrative:
Warehouse club operations	53,203	48,213	104,975	94,055
General and administrative	13,277	11,888	24,461	23,046
Pre-opening expenses	340	147	814	886
Loss/(gain) on disposal of assets	104	47	188	104
Total operating expenses	634,999	571,006	1,208,241	1,076,581
Operating income	39,375	36,404	71,734	66,115
Other income (expense):
Interest income	193	446	374	740
Interest expense	(886)	(1,306)	(1,924)	(2,524)
Other income (expense), net	712	(265)	1,023	(264)
Total other expense	19	(1,125)	(527)	(2,048)
Income from continuing operations before provision for income taxes and loss of unconsolidated affiliates	39,394	35,279	71,207	64,067
Provision for income taxes	(11,116)	(10,393)	(21,501)	(19,172)
Income (loss) of unconsolidated affiliates	0	(4)	4	(8)
Net income	$ 28,278	$ 24,882	$ 49,710	$ 44,887
Net income per share available for distribution:
Basic net income per share from continuing operations (in dollars per share)	$ 0.93	$ 0.82	$ 1.64	$ 1.48
Basic net income per share (in dollars per share)	$ 0.93	$ 0.82	$ 1.64	$ 1.48
Diluted net income per share from continuing operations (in dollars per share)	$ 0.93	$ 0.82	$ 1.64	$ 1.48
Diluted net income per share (in dollars per share)	$ 0.93	$ 0.82	$ 1.64	$ 1.48
Shares used in per share computations:
Basic (in shares)	29,724	29,626	29,707	29,609
Diluted (in shares)	29,736	29,636	29,719	29,620
Dividends per share (in dollars per share)	$ 0.70	$ 0.00	$ 0.70	$ 0.60
Statement [Line Items]
Document Fiscal Year Focus			2014