CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Aug. 31, 2014	Aug. 31, 2013		Aug. 31, 2012
Revenues [Abstract]
Net warehouse club sales	$ 2,444,314	$ 2,239,266		$ 1,999,364
Export sales	31,279	23,059		15,320
Membership income	38,063	33,820		26,957
Other income	3,911	3,667		3,522
Total revenues	2,517,567	2,299,812		2,045,163
Cost of Goods Sold [Abstract]
Net warehouse club	2,083,933	1,907,632		1,701,332
Export	29,731	21,796		14,649
Selling, General and Administrative Expense [Abstract]
Warehouse club operations	212,476	194,140		179,618
General and Administrative Expense	49,944	46,784		41,021
Pre-Opening Costs	3,331	1,525		617
Loss/(gain) on disposal of assets	1,445	889		312
Total operating expenses	2,380,860	2,172,766		1,937,549
Operating Income (Loss)	136,707	127,046		107,614
Nonoperating Income (Expense) [Abstract]
Interest Income	853	1,335		908
Interest expense	(4,295)	(4,216)		(5,283)
Other Nonoperating Income (Expense)	984	(954)		(525)
Total other income (expense)	(2,458)	(3,835)		(4,900)
Income from continuing operations before provision for income taxes and loss of unconsolidated affiliates	134,249	123,211		102,714
Provision for income taxes	(41,372)	(38,942)		(35,053)
Income (Loss) of unconsolidated affiliates	9	(4)		(15)
Income from continuing operations	92,886	84,265		67,646
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	0	0		(25)
Net income	$ 92,886	$ 84,265	[1]	$ 67,621
Net income per share
Income (Loss) from Continuing Operations, Per Basic Share	$ 3.07	$ 2.78		$ 2.24
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	$ 0.00	$ 0.00		$ 0.00
Basic net income per share	$ 3.07	$ 2.78	[1]	$ 2.24
Income (Loss) from Continuing Operations, Per Diluted Share	$ 3.07	$ 2.78		$ 2.24
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	$ 0.00	$ 0.00		$ 0.00
Diluted net income per share	$ 3.07	$ 2.78	[1]	$ 2.24
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Weighted Average Number of Shares Outstanding, Basic	29,747	29,647		29,554
Weighted Average Number of Shares Outstanding, Diluted	29,757	29,657		29,566
Common Stock, Dividends, Per Share, Declared	$ 0.70	$ 0.60		$ 0.60

[1] (1) The fiscal year 2013 and 2012 data has been updated to reflect the reclassifications as disclosed in Note 1 - Company Overview and Basis of Presentation.