Fair Value Measurements - Fair Value Reconciliation Liabilities Using Significant Unobservable Inputs (Level 3) (Details) - NCRA [Member] - Crack Spread Contingent Payment [Member] - USD ($) $ in Thousands	3 Months Ended
	Nov. 30, 2016	Nov. 30, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 15,051	$ 78,982
Ending Balance	8,281	46,693
Cost of Goods, Total
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total (gains) losses included in cost of goods sold	$ (6,770)	$ (32,289)