Other Assets - Schedule of Other Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2010
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 85,063	$ 81,693	$ 26,409
Finite-lived intangible assets, net	35,476
Notes receivable	143,343	173,054
Long-term receivable	38,704	37,589
Prepaid pension and other benefits	187,270	86,477
Capitalized major maintenance	109,408	70,554	80,752	19,097
Other	56,896	24,053
Other Assets	656,160	518,286
Amortization of intangible assets	10,000	12,700	11,000
Customer lists
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	16,352	20,694
Amortization of intangible assets	20,063	32,883
Non-compete covenants
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	812	1,987
Amortization of intangible assets	6,129	6,896
Trademarks and other intangible assets
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	18,312	22,185
Amortization of intangible assets	$ 19,853	$ 15,949