Long-Term Debt - Additional Information (Detail) - MidCap Financial Credit Agreement [Member] - Senior Secured Term Loan [Member] - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2015	Jun. 26, 2015
Debt Instrument [Line Items]
Current borrowing capacity			$ 20,000,000
Additional borrowing capacity			20,000,000
Maximum borrowing capacity			$ 40,000,000
Credit Agreement interest rate per annum	7.75%	7.75%
Interest payment due date		Jun. 30, 2016
Origination fee, percentage		0.50%
Final payment fee, percentage		2.00%
Monthly principal payments commencement date		Jul. 01, 2016
Periodic principal payment frequency		Monthly
Monthly principal payments		$ 800,000
Monthly principal payments if the facility increased by additional borrowings		1,700,000
Long-term debt	$ 20,000,000	$ 20,000,000
Debt instrument prepayment fee percent within twelve months		2.95%
Debt instrument prepayment fee percent on or after twelve months		2.00%
Minimum cash balance as collateral	15,000,000	$ 15,000,000
Debt issuance costs		800,000
Maximum [Member]
Debt Instrument [Line Items]
Interest expenses on term loans	$ 400,000	$ 500,000

Debt instrument final payment fee percentage.

No definition available.

Name:	srpt_DebtInstrumentFinalPaymentFeePercentage
Namespace Prefix:	srpt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument interest payment due date.

+ References

No definition available.

+ Details

Name:	srpt_DebtInstrumentInterestPaymentDueDate
Namespace Prefix:	srpt_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument origination fee percentage.

+ References

No definition available.

+ Details

Name:	srpt_DebtInstrumentOriginationFeePercentage
Namespace Prefix:	srpt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument prepayment after twelve months fee percent.

+ References

No definition available.

+ Details

Name:	srpt_DebtInstrumentPrepaymentAfterTwelveMonthsFeePercent
Namespace Prefix:	srpt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument prepayment fee percentage made within twelve months.

+ References

No definition available.

+ Details

Name:	srpt_DebtInstrumentPrepaymentFeePercentageMadeWithinTwelveMonths
Namespace Prefix:	srpt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility, additional borrowing capacity.

+ References

No definition available.

+ Details

Name:	srpt_LineOfCreditFacilityAdditionalBorrowingCapacity
Namespace Prefix:	srpt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of credit facility additional borrowings periodic payment principal.

+ References

No definition available.

+ Details

Name:	srpt_LineOfCreditFacilityAdditionalBorrowingsPeriodicPaymentPrincipal
Namespace Prefix:	srpt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line of credit facility covenant minimum cash required to be maintained.

+ References

No definition available.

+ Details

Name:	srpt_LineOfCreditFacilityCovenantMinimumCashRequiredToBeMaintained
Namespace Prefix:	srpt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

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.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of debt issuance costs (for example, but not limited to, legal, accounting, broker, and regulatory fees).

+ References

No definition available.

+ Details

Name:	us-gaap_DebtIssuanceCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.8)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

Name:	us-gaap_InterestExpenseDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References