Name:	fenc_DaysFollowingReceiptOfNoticeLetterToFilePatentInfringementSuit
Namespace Prefix:	fenc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Days notice required by Fennec to terminate OHSU agreement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

No definition available.

Name:	fenc_DaysNoticeRequiredByFennecToTerminateOhsuAgreement
Namespace Prefix:	fenc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Days notice required to terminate OHSU agreement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

No definition available.

Name:	fenc_DaysNoticeToTerminateOhsuAgreement
Namespace Prefix:	fenc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Duration of FDA's ability to give final approval to proposed products that reference PEDMARK subsequent to the filing of a patent infringement suit, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

No definition available.

Name:	fenc_DurationOfFdaSAbilityToGiveFinalApprovalToProposedProductsThatReferencePedmark
Namespace Prefix:	fenc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Licensing term under OHSU agreement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

No definition available.

Name:	fenc_LicensingTermOhsuAgreement
Namespace Prefix:	fenc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents number of severance payments following executive's termination.

No definition available.

Name:	fenc_NumberOfSeverancePayments
Namespace Prefix:	fenc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Days notice required to terminate lease agreement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

No definition available.

Name:	fenc_OperatingLeaseDaysNoticeRequiredToTerminateAgreement
Namespace Prefix:	fenc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents number of scheduled payment increases over the duration of the lease agreement.

No definition available.

Name:	fenc_OperatingLeaseNumberOfScheduledPaymentIncreases
Namespace Prefix:	fenc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Amount of operating lease penalties and contingent payments due.

No definition available.

Name:	fenc_OperatingLeasePenaltiesAndContingentPaymentsPayable
Namespace Prefix:	fenc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Duration of PEDMARK's exclusivity period due to Orphan Drug Exclusivity status, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

No definition available.

Name:	fenc_PedmarkSOrphanDrugExclusivityPeriod
Namespace Prefix:	fenc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the percentage of royalties to be received as consideration.

No definition available.

Name:	fenc_RoyaltiesPercentage
Namespace Prefix:	fenc_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Amount of operating lease expense. Excludes sublease income.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 4
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123391704&loc=SL77918638-209977

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

Describes the maximum potential amount of consideration, undiscounted, that could be transferred under the registration payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=99383193&loc=d3e16207-108621

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

Describes the term of the registration payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=99383193&loc=d3e16207-108621

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

Amount of expense related to royalty payments under a contractual arrangement such as payment for mineral and drilling rights and use of technology or intellectual property.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

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

This element represents money paid in advance to protect the provider of a product or service, such as a lessor, against damage or nonpayment by the buyer or tenant (lessee) during the term of the agreement. Such damages may include physical damage to the property, theft of property, and other contractual breaches. Security deposits held may be interest or noninterest bearing.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.15(a))
-URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

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

Name:	us-gaap_OtherCommitmentsAxis=fenc_OregonHealthAndScienceUniversityAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_OtherCommitmentsAxis=fenc_LeaseContingenciesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_StatementGeographicalAxis=fenc_TriangleParkNorthCarolinaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_StatementGeographicalAxis=fenc_HobokenNewJerseyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_StatementScenarioAxis=fenc_OfficeServiceAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_OtherCommitmentsAxis=fenc_LitigationCiplaAndaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_OtherCommitmentsAxis=fenc_ExecutiveSeveranceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_TitleOfIndividualAxis=srt_ChiefExecutiveOfficerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: