Segment Information - Summary of Total Assets from Segments to Consolidated (Parenthetical) (Details) - USD ($) $ in Thousands	May 31, 2020	Aug. 31, 2019
Segment Reporting Information [Line Items]
Investments in joint ventures	$ 9,905	$ 10,276
AMR
Segment Reporting Information [Line Items]
Investments in joint ventures	2,000	3,000
CSS
Segment Reporting Information [Line Items]
Investments in joint ventures	$ 7,000	$ 7,000

Amount of investment in equity method investee and investment in and advance to affiliate.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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