Asset Acquisitions - Summary of Assets Acquired and Liabilities Assumed (Detail) $ in Thousands	Dec. 31, 2019 USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Other assets and liabilities	$ 1,237
Total net assets acquired	38,561
In-process research and development [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets	36,899
Intangible assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 425