CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	May. 31, 2015	Aug. 31, 2014
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 10,767	$ 1,994
Property, plant and equipment, accumulated depreciation	2,139,972	1,923,750
Intangible assets, accumulated amortization	$ 188,503	$ 171,490
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	246,066,250	243,930,983
Common stock, shares outstanding	193,827,796	194,113,850
Treasury stock, shares	52,238,454	49,817,133