Inventories - Schedule of Inventories (Details) - USD ($) $ in Thousands	Nov. 30, 2017	Aug. 31, 2017
Inventory Disclosure [Abstract]
Grain and oilseed	$ 1,545,313	$ 1,145,285
Energy	720,938	755,886
Crop nutrients	222,053	248,699
Feed and farm supplies	483,805	353,130
Processed grain and oilseed	54,916	49,723
Other	19,076	23,862
Total inventories	$ 3,046,101	$ 2,576,585