Restatement of Previously Issued Financial Statements - Reconciliation of Sales and Cost of Sales (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Nov. 30, 2012	Nov. 30, 2011
Sales	$ 118,022	$ 108,168
Cost of sales	104,764	96,360
Industrial Ingredients [Member]
Sales	90,368	82,244
As Previously Reported [Member]
Sales	94,859	90,746
Cost of sales	81,601	78,938
As Previously Reported [Member] | Industrial Ingredients [Member]
Sales	67,205	64,822
Adjustment [Member]
Sales	23,163	17,422
Cost of sales	23,163	17,422
Adjustment [Member] | Industrial Ingredients [Member]
Sales	$ 23,163	$ 17,422