Name:	fenc_DaysFollowingReceiptOfNoticeLetterToFilePatentInfringementSuit
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

Period of months (at the executive's then-current base salary) used to determine initial severance payment in the event of employment termination "without cause," in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

No definition available.

Name:	fenc_ExecutiveSeveranceMonthsOfCurrentBaseSalaryPayable
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

Term over which severance payments will be made in the event of employment termination, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

No definition available.

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

The variable rate of interest (added to the current prime interest rate) used in determining the Company's incremental borrowing rate.

No definition available.

Name:	fenc_VariableInterestRateOverPrime
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
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 4
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479041/842-20-45-4

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
-Name Accounting Standards Codification
-Topic 825
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482804/825-20-50-1

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

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.

No definition available.

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

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:	srt_StatementScenarioAxis=fenc_SecondOfficeServiceAgreementMember
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: