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

A general description of the nature of the existing leasing arrangements of a lessor for all operating leases including, but not limited to: (1) guarantees or indemnities; (2) restrictions imposed by lease arrangements; (3) unusual provisions or conditions; (4) contingent rentals; and (5) lease expiration dates.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=84164561&loc=d3e37045-112695

Name:	us-gaap_DescriptionOfLessorLeasingArrangementsOperatingLeases
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Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

No definition available.

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

Date which lease or group of leases is set to expire, in CCYY-MM-DD format.

No definition available.

Name:	us-gaap_LeaseExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

Term of lessor's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888428&loc=SL77919359-209981

Name:	us-gaap_LessorOperatingLeaseRenewalTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

Term of the unrecognized unconditional purchase obligation, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77896938&loc=d3e25336-109308

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Agreement terminated in exchange for a one-time payment.

No definition available.

Name:	xene_AgreementTerminatedInExchangeForOneTimePayment
Namespace Prefix:	xene_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Commitments and contingencies.

No definition available.

Name:	xene_CommitmentsAndContingenciesLineItems
Namespace Prefix:	xene_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Contractual obligation paid.

No definition available.

Name:	xene_ContractualObligationPaid
Namespace Prefix:	xene_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Future potential payments.

No definition available.

Name:	xene_FuturePotentialPayments
Namespace Prefix:	xene_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

License manufacture and supply agreement upfront fee.

No definition available.

Name:	xene_LicenseManufactureAndSupplyAgreementUpfrontFee
Namespace Prefix:	xene_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Milestone payments paid.

No definition available.

Name:	xene_MilestonePaymentsPaid
Namespace Prefix:	xene_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Royalty obligations.

No definition available.

Name:	xene_RoyaltyObligations
Namespace Prefix:	xene_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Upfront fee paid.

No definition available.

Name:	xene_UpfrontFeePaid
Namespace Prefix:	xene_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Name:	us-gaap_TypeOfArrangementAxis=xene_AssetPurchaseAgreementMember
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Name:	srt_CounterpartyNameAxis=xene_FirstOrderPharmaceuticalsIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis=xene_ClinicalDevelopmentMilestonesMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis=xene_RegulatoryMilestoneMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	srt_RangeAxis=srt_MaximumMember
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Name:	us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis=xene_OtherMilestonesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CounterpartyNameAxis=xene_FirstOrderPharmaceuticalsIncAndBauschHealthCompaniesIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_TypeOfArrangementAxis=xene_LicenseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=xene_MedpaceClinicalDevelopmentServiceAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: