Payment Obligation Under 2009 Settlement Agreement (Detail) $ in Thousands	Mar. 31, 2021 USD ($)
Related Party Transaction [Line Items]
2021 (remaining nine months)	$ 14,845
Total	15,010
Settlement Agreement
Related Party Transaction [Line Items]
2021 (remaining nine months)	812
Present value discount factor	(24)
Total	$ 788

Amount of purchase arrangement to be paid in remainder of current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment.

No definition available.

Name:	us-gaap_PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant