Identifiable Intangible and Other Assets (Detail) (USD $) In Thousands, unless otherwise specified	Nov. 30, 2012	Aug. 31, 2012
Intangible Assets by Major Class [Line Items]
Finite-Lived Intangible Assets, Net	$ 43,742	$ 44,957
Intangible assets not subject to amortization	912	912
Prepaid and other assets	10,140	10,272
Debt issuance costs, net	9,562	10,194
Nonqualified savings plan investments	6,771	6,667
Investment in unconsolidated affiliates	8,373	8,301
Investment in direct finance leases		65
Total intangible and other assets	79,500	81,368
Customer Relationships
Intangible Assets by Major Class [Line Items]
Finite lived intangible assets gross	66,825	66,825
Accumulated amortization	(24,153)	(22,995)
Other Intangible Assets
Intangible Assets by Major Class [Line Items]
Finite lived intangible assets gross	5,003	4,906
Accumulated amortization	$ (3,933)	$ (3,779)