Warranties (Schedule Of Product Warranty Liability) (Details) (USD $)	12 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2010
Warranties [Abstract]
Product warranty accrual balance, beginning of period	$ 3,651,000	$ 1,862,000
Liabilities accrued for warranties during the period	4,922,000	4,865,000
Warranty claims paid during the period	(3,725,000)	(3,076,000)
Product warranty accrual balance, end of period	4,848,000	3,651,000	1,862,000
Warranty costs	$ 4,900,000	$ 4,900,000	$ 3,800,000