Property, Plant and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		17 Months Ended
	May. 31, 2015	May. 31, 2014	May. 31, 2015	May. 31, 2014	May. 31, 2015	Aug. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 4,648,282		$ 4,648,282		$ 4,648,282	$ 4,031,023
Depreciation	$ 75,800	$ 62,400	219,000	$ 182,500
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Additions			540,500
Spiritwood [Member]
Property, Plant and Equipment [Line Items]
Total construction cost, estimate			$ 3,000,000
Spiritwood [Member] | Asset under Construction [Member]
Property, Plant and Equipment [Line Items]
Acquisition of property, plant and equipment					$ 74,400