Restructuring and related activities initiation month and year.

No definition available.

Name:	srpt_RestructuringAndRelatedActivitiesInitiationMonthAndYear
Namespace Prefix:	srpt_
Data Type:	xbrli:gYearMonthItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflow for the obligation for a lease meeting the criteria for capitalization (with maturities exceeding one year or beyond the operating cycle of the entity, if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

+ Details

Name:	us-gaap_RepaymentsOfLongTermCapitalLeaseObligations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Date the exit and disposal activities were completed or are expected to be completed, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(a))
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

+ Details

Name:	us-gaap_RestructuringAndRelatedActivitiesCompletionDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

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

- Definition

Amount, after cash payment, of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

+ Details

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

- Details

Name:	us-gaap_RestructuringPlanAxis=srpt_CorvallisPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=us-gaap_FacilityClosingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Restructuring - Additional Information (Detail) - Corvallis Plan [Member] - USD ($) $ in Millions	1 Months Ended		3 Months Ended
	Apr. 30, 2017	Dec. 31, 2016	Mar. 31, 2018
Restructuring Cost And Reserve [Line Items]
Restructuring, initiation date			2016-03
Restructuring, completion date			Dec. 31, 2017
Minimum lease payment obligation			$ 4.5
Facility Closing [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring expenses	$ 2.3	$ 1.5