Goodwill And Other Intangible Assets (Schedule Of Intangible Assets)(Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Aug. 31, 2012	Aug. 31, 2011
Finite And Indefinite Intangible Assets [Line Items]
Weighted average life	11 years 3 months 18 days
Amortizable intangible assets, gross	$ 39,573	$ 40,429
Accumulated amortization	(14,503)	(11,790)
Trade Names [Member]
Finite And Indefinite Intangible Assets [Line Items]
Amortizable intangible assets, gross	6,575	6,719
Customer Relationships [Member]
Finite And Indefinite Intangible Assets [Line Items]
Weighted average life	8 years 4 months 24 days	9 years 8 months 12 days
Amortizable intangible assets, gross	6,313	6,371
Accumulated amortization	(3,477)	(2,768)
Noncompete Agreements [Member]
Finite And Indefinite Intangible Assets [Line Items]
Weighted average life	5 years 6 months	6 years 10 months 24 days
Amortizable intangible assets, gross	846	852
Accumulated amortization	(478)	(320)
Other Intangible Assets [Member]
Finite And Indefinite Intangible Assets [Line Items]
Amortizable intangible assets, gross	202	171
Accumulated amortization	(90)	(41)
Patents [Member]
Finite And Indefinite Intangible Assets [Line Items]
Weighted average life	12 years 8 months 12 days	13 years 1 month 6 days
Amortizable intangible assets, gross	25,637	26,316
Accumulated amortization	$ (10,458)	$ (8,661)