The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value.

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License and Acquired Intangibles, Net - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets			$ 23,506	$ 518
Impairment charges recognized on definite-lived intangibles	$ 0	$ 0	$ 0	0
Finite-Lived Intangible Assets, Remaining Amortization Period	6 years		6 years		14 years
License and Acquired Intangibles for RUZURGI [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	14 years 6 months		14 years 6 months
Amortization of intangible assets	$ 600	$ 500	$ 1,800	$ 500
License and Acquired Intangibles for FYCOMPA [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	5 years		5 years
Amortization of intangible assets	$ 7,900		$ 21,800