Concentrations of Risk - Additional Information (Detail)	Nov. 30, 2018 USD ($)
Concentration Risk [Line Items]
Cash balances not federally insured	$ 79,000,000
Maximum [Member]
Concentration Risk [Line Items]
Maximum insurance available to depositors under the FDIC's general deposit insurance rules	$ 250,000

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_ConcentrationRiskLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration