Fair Value Measurements (Tables)

6 Months Ended

Feb. 28, 2017

Fair Value Disclosures [Abstract]

Fair Value Measurements, Recurring and Nonrecurring

	February 28, 2017
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
	(Dollars in thousands)
Assets:
Commodity and freight derivatives	$	28,220	$	319,924	$	—	$	348,144
Foreign currency derivatives	—		27,548		—		27,548
Interest rate swap derivatives	—		6,892		—		6,892
Deferred compensation assets	50,599		—		—		50,599
Embedded derivative asset	—		24,569		—		24,569
Other assets	14,133		—		—		14,133
Total	$	92,952	$	378,933	$	—	$	471,885
Liabilities:
Commodity and freight derivatives	$	17,960	$	236,658	$	—	$	254,618
Foreign currency derivatives	—		18,537		—		18,537
Interest rate swap derivatives	—		2,329		—		2,329
Crack spread contingent consideration liability	—		—		2,172		2,172
Total	$	17,960	$	257,524	$	2,172	$	277,656

	August 31, 2016
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
	(Dollars in thousands)
Assets:
Commodity and freight derivatives	$	62,538	$	437,654	$	—	$	500,192
Foreign currency derivatives	—		21,551		—		21,551
Interest rate swap derivatives	—		22,078		—		22,078
Deferred compensation assets	50,099		—		—		50,099
Other assets	12,678		—		—		12,678
Total	$	125,315	$	481,283	$	—	$	606,598
Liabilities:
Commodity and freight derivatives	$	22,331	$	468,971	$	—	$	491,302
Foreign currency derivatives	—		22,289		—		22,289
Interest rate swap derivatives	—		8		—		8
Crack spread contingent consideration liability	—		—		15,051		15,051
Total	$	22,331	$	491,268	$	15,051	$	528,650

Fair Value Inputs, Liabilities, Quantitative Information

Quantitative Information about Level 3 Fair Value Measurements
Item	Fair Value February 28, 2017 (Dollars in thousands)	Valuation Technique	Unobservable Input	Input Used
Crack spread contingent consideration liability	$2,172	Adjusted Black-Scholes option pricing model	Forward crack spread margin quotes on February 28, 2017 (a)	$11.86
			Contractual target crack spread margin (b)	$17.50
			Expected volatility (c)	87.68%
			Risk-free interest rate (d)	0.94%
			Expected life - years (e)	0.50

^(a) Represents forward crack spread margin quotes and management estimates based on the future settlement date.

^(b) Represents the minimum contractual threshold that would require settlement with the counterparties.

^(c) Represents quarterly adjusted volatility estimates derived from daily historical market data.

^(d) Represents yield curves for U.S. Treasury securities.

^(e) Represents the number of years remaining related to the final contingent payment.

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation

The following table represents a reconciliation of liabilities measured at fair value using significant unobservable inputs (Level 3) for the three months endedFebruary 28, 2017, and February 29, 2016.

	Level 3 Liabilities
	Crack spread contingent consideration liability
	2017			2016
	(Dollars in thousands)
Balances, November 30, 2016 and 2015, respectively	$	8,281		$	43,693
Total (gains) losses included in cost of goods sold	(6,109		)	(19,538		)
Balances, February 28, 2017, and February 29, 2016, respectively	$	2,172		$	24,155

The following table represents a reconciliation of liabilities measured at fair value using significant unobservable inputs (Level 3) for the six months ended February 28, 2017, and February 29, 2016.

	Level 3 Liabilities
	Crack spread contingent consideration liability
	2017			2016
	(Dollars in thousands)
Balances, August 31, 2016, and 2015, respectively	$	15,051		$	75,982
Total (gains) losses included in cost of goods sold	(12,879		)	(51,827		)
Balances, February 28, 2017 and February 29, 2016, respectively	$	2,172		$	24,155