Intangibles - Components of Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Finite Lived Intangible Assets [Line Items]
Intangible assets, Net Carrying Value	$ 1,809	$ 1,864
License Agreements [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, Gross Carrying Value	3,117	3,117
Intangible assets, Accumulated Amortization	(1,308)	(1,253)
Intangible assets, Net Carrying Value	$ 1,809	$ 1,864