Intangible Assets, Net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jul. 31, 2017
Finite Lived Intangible Assets [Line Items]
Amortization of in-licensed rights	$ 714	$ 706	$ 662
Patents [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of in-licensed rights	1,100	600	600
Patents [Member] | Research and Development Expense [Member]
Finite Lived Intangible Assets [Line Items]
Book value of patent abandoned	6,000	500	100
Software Development [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of in-licensed rights		$ 100	$ 500
Minimum [Member] | Software Development [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of in-licensed rights	100
EXONDYS 51 [Member]
Finite Lived Intangible Assets [Line Items]
In-lincensed Rights	1,000
EXONDYS 51 [Member] | Maximum [Member] | Bio Marin [Member]
Finite Lived Intangible Assets [Line Items]
Sales milestone payment recorded as an in-license right				$ 6,600
VYONDYS 53 [Member]
Finite Lived Intangible Assets [Line Items]
In-lincensed Rights	500
AMONDYS 45
Finite Lived Intangible Assets [Line Items]
In-lincensed Rights	$ 500