Contingencies and Other Accrued Losses - Additional Information (Detail) $ in Millions	3 Months Ended
Nov. 30, 2018 USD ($)
Commitments And Contingencies Disclosure [Abstract]
Litigation settlement amount	$ 6.5

Amount awarded to other party in judgment or settlement of litigation.

No definition available.

Name:	us-gaap_LitigationSettlementAmountAwardedToOtherParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration