Restatement of Previously Issued Financial Information - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Nov. 30, 2018	Nov. 30, 2017	Aug. 31, 2017	Aug. 31, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase (decrease) to income before income taxes	$ 367,232	$ 207,788
Increase (decrease) to net income	347,115	187,182
Decrease in cash	(266,152)	(249,767)	$ (181,379)	$ (450,617)
Increase (decrease) to cost of goods sold	8,013,648	7,711,392
Increase (decrease) to income tax expense	20,117	20,606
Increase (decrease) to revenues	8,484,289	8,031,884
Misstatement between line items in the Consolidated Statements of Cash Flows			3,000
Decrease of inventory	$ (3,184,449)			$ (2,768,649)
Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase (decrease) to income before income taxes		8,233
Increase (decrease) to net income		7,563
Increase (decrease) to cost of goods sold		(24,570)
Increase (decrease) to income tax expense		670
Increase (decrease) to revenues		(17,005)
Freight Derivatives and Related Misstatements
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Misstatement between line items in the Consolidated Statements of Cash Flows		3,000
Freight Derivatives and Related Misstatements | Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase (decrease) to income before income taxes		(500)
Increase (decrease) to net income		(1,200)
Increase (decrease) to cost of goods sold		500
Increase (decrease) to income tax expense		700
Intercompany Misstatements
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Misstatement between line items in the Consolidated Statements of Cash Flows		3,000
Intercompany Misstatements | Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Decrease in cash		2,400
Increase (decrease) to revenues		(11,400)
Other Misstatements | Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase (decrease) to income before income taxes		8,800
Misstatement between line items in the Consolidated Statements of Cash Flows		18,300	18,300
Reduction of notes payable		3,100
Other Misstatements, Reclassification, Unit of Measure Assumption Adjustment | Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase (decrease) to cost of goods sold		(6,200)
Other Misstatements, Postretirement Benefit Plan Activity | Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase (decrease) in costs related to postretirement benefit plan activity		(2,600)
Other Misstatements, Reclassification, Application of Accounting Policies | Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase (decrease) to revenues		(5,700)
Other Misstatements, Timing Difference | Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Negative cash balance		$ 10,400
Decrease of inventory			24,100
Increase in accounts receivable			$ 24,100