Background - Additional Information (Detail) $ in Thousands	9 Months Ended
Sep. 30, 2022 USD ($) Segment	Dec. 31, 2021 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Entity incorporation date	Nov. 15, 2007
Accumulated deficit \| $	$ 256,466	$ 245,754
Number of operating segment \| Segment	1

The cumulative amount of the reporting entity's undistributed earnings or deficit.

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