Acquisitions (Details) - Acquisition of Biscayne Neurotherapeutics, Inc. $ in Millions		12 Months Ended
Oct. 04, 2018 USD ($)	Dec. 31, 2018 USD ($)
Acquisitions
Upfront cash payment	$ 15
Maximum combined royalty (as a percent)	12
Developmental milestones related to intellectual property \| Maximum
Acquisitions
Contingent consideration based on milestones	$ 73
Sales milestones related to marketing products developed from intellectual property assets \| Maximum
Acquisitions
Contingent consideration based on milestones	$ 95
Fair value measurement, nonrecurring
Acquisitions
Deferred tax asset		$ 1
Fair value measurement, nonrecurring \| In-process research and development
Acquisitions
Research and development expense		14
Cash paid for in-process research and development asset		$ 15

No definition available.

Name:	supn_AssetAcquisitionContingentConsiderationLiability
Namespace Prefix:	supn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of deferred tax asset attributable to deductible temporary differences and carryforwards acquired in the asset acquisition.

+ References

No definition available.

+ Details

Name:	supn_AssetAcquisitionDeferredTaxAsset
Namespace Prefix:	supn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of upfront cash payment made in consideration for the fair value of assets acquired in the asset acquisition.

+ References

No definition available.

+ Details

Name:	supn_AssetAcquisitionInitialUpfrontCashPayment
Namespace Prefix:	supn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the maximum percentage of royalty to be paid to all combined parties on net sales to the former security holders, and any applicable royalties to third parties for the use of in-licensed intellectual property.

+ References

No definition available.

+ Details

Name:	supn_AssetAcquisitionMaximumPercentageOfCombinedRoyalty
Namespace Prefix:	supn_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflows associated with in-process research and development asset in an asset acquisition.

+ References

No definition available.

+ Details

Name:	supn_AssetAcquisitionPaymentsToAcquireInProcessResearchAndDevelopment
Namespace Prefix:	supn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of research and development expense recognised in an asset acquisition.

+ References

No definition available.

+ Details

Name:	supn_AssetAcquisitionResearchAndDevelopmentExpense
Namespace Prefix:	supn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=supn_AcquisitionOfBiscayneNeurotherapeuticsIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ContingentConsiderationByTypeAxis=supn_DevelopedIntellectualPropertyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ContingentConsiderationByTypeAxis=supn_DevelopedProductsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_InProcessResearchAndDevelopmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: