Benefit Plans - Information for the Pension Plans with an Accumulated Benefit Obligation in Excess of Plan Assets (Details) - USD ($) $ in Thousands	Aug. 31, 2019	Aug. 31, 2018
Retirement Benefits [Abstract]
Projected benefit obligation	$ 19,047	$ 20,755
Accumulated benefit obligation	$ 16,907	$ 18,586

Amount of accumulated benefit obligation for defined benefit pension plan with projected benefit obligation in excess of plan assets.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e2417-114920

Name:	us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsAccumulatedBenefitObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant