Long-Term Debt - Long-Term Debt (Parenthetical) (Detail)	Dec. 31, 2020
6.75% Senior Secured Notes [Member] \| Debt Issuance Costs [Member]
Debt Instrument [Line Items]
Imputed interest rate percentage	7.08%

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