Commitments and Contingencies - Additional Information (Detail) $ in Thousands	1 Months Ended	9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2015 USD ($)
Commitments And Contingencies Disclosure [Abstract]
Letters of credit amount issued	$ 10,700	$ 10,700
Certificate of deposit purchased	10,695	$ 10,695
Certificate of deposit maturity date		2016-09
Restricted investments	$ 10,700	$ 10,700
Number of days to amend plaintiffs complaint		28 days
Law affected under lawsuit filling		The consolidated amended complaint alleged that Sarepta and certain of its officers violated the federal securities laws in connection with disclosures related to eteplirsen