Long-Term Debt - Additional Information (Detail) $ in Millions	Mar. 31, 2018 USD ($)
Credit facility \| Line of Credit
Debt Instrument [Line Items]
Borrowing limit used	$ 1.0

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