Customer Concentration - Additional Information (Detail)	12 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2010
Customer One Concentration Risk
Concentration Risk [Line Items]
Percentage of total revenues	26.00%	19.00%	16.00%
Customer Two Concentration Risk
Concentration Risk [Line Items]
Percentage of total revenues	16.00%	14.00%	15.00%
Customer Three Concentration Risk
Concentration Risk [Line Items]
Percentage of total revenues	11.00%	12.00%	11.00%
Customer Four Concentration Risk
Concentration Risk [Line Items]
Percentage of total revenues		11.00%
Customer Concentration Risk
Concentration Risk [Line Items]
Customers accounted for more than 10% of total revenues	0	0	0
Customer Concentration Risk | Two Customers
Concentration Risk [Line Items]
Customer that equaled or exceeded 10% of accounts receivable and in total represented 30% of the consolidated accounts receivable	1
Percentage of accounts receivable balance	13.00%
Customer Concentration Risk | Only one customer
Concentration Risk [Line Items]
Customer that equaled or exceeded 10% of accounts receivable and in total represented 30% of the consolidated accounts receivable		2
Percentage of accounts receivable balance		30.00%