License and Acquired Intangibles, Net - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 9,345,000	$ 9,344,000
Impairment charges recognized on definite-lived intangibles	$ 0	0
Finite-Lived Intangible Assets, Remaining Amortization Period	5 years 2 months 12 days		5 years 4 months 24 days
License and Acquired Intangibles for RUZURGI [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	14 years 6 months
Amortization of intangible assets	$ 600,000	600,000
License and Acquired Intangibles for FYCOMPA [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	5 years
Amortization of intangible assets	$ 7,900,000	7,900,000
Licensed And Acquired Intangibles For AGAMREE [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	10 years 6 months
Amortization of intangible assets	$ 900,000	$ 900,000