Goodwill and Other Intangible Assets (Details) (USD $) In Thousands	Aug. 31, 2011	Aug. 31, 2010
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 49,682	$ 73,909
Accumulated Amortization	17,344	25,627
Net Carrying Amount	32,338	48,282
Customer base [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	34,128	56,423
Accumulated Amortization	12,714	17,453
Net Carrying Amount	21,414	38,970
Non-competition agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,183	9,984
Accumulated Amortization	3,281	7,211
Net Carrying Amount	902	2,773
Favorable land leases [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	7,063	5,728
Accumulated Amortization	521	388
Net Carrying Amount	6,542	5,340
Brand name [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,207	1,509
Accumulated Amortization	803	557
Net Carrying Amount	3,404	952
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	101	265
Accumulated Amortization	25	18
Net Carrying Amount	$ 76	$ 247