Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Aug. 31, 2011	Aug. 31, 2010
Consolidated Balance Sheets
Trade accounts receivable, allowance for doubtful accounts	$ 4,788	$ 13,939
Property, plant and equipment, accumulated depreciation	1,363,481	1,166,807
Intangible assets, accumulated amortization	$ 128,467	$ 112,687
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	224,653,990	219,532,908
Common stock, shares outstanding	203,416,503	210,496,989
Treasury shares	21,237,487	9,035,919