Fair Value of Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Mar. 07, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Percentage of probability of achieving milestone	72.00%	67.00%
Commercial milestones in applicable revenue, 2024	$ 100.0
Commercial milestones in applicable revenue, 2025	200.0
Essentialis, Inc. [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Maximum potential cash earnout payments	$ 21.2		$ 30.0