Derivative Financial Instruments and Hedging Activities - Location and Carrying Amount of Hedged Liabilities (Details) - Designated as Hedging Instrument - Long-term debt - USD ($) $ in Thousands	Aug. 31, 2018	Aug. 31, 2017
Derivative [Line Items]
Carrying Amount of Hedged Liabilities	$ 485,548	$ 504,271
Cumulative Amount of Fair Value Hedging Adjustments Included in the Carrying Amount of Hedged Liabilities	$ 9,452	$ (9,271)

Net fair value of all derivative instruments designated as fair value hedging instruments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

Name:	us-gaap_FairValueHedgesAtFairValueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant