Consolidation, Noncontrolling Interests and Basis of Presentation - Additional Information (Detail)	Aug. 31, 2018	Aug. 31, 2017
Accounting Policies [Abstract]
Percentage of controlled subsidiary's earnings	100.00%	100.00%

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant