v3.26.1
Cover
Jun. 10, 2026
Cover [Abstract]  
Document Type 8-K
Amendment Flag false
Document Period End Date Jun. 10, 2026
Entity File Number 001-32295
Entity Registrant Name FENNEC PHARMACEUTICALS INC.
Entity Central Index Key 0001211583
Entity Tax Identification Number 20-0442384
Entity Incorporation, State or Country Code A1
Entity Address, Address Line One PO Box 13628
Entity Address, Address Line Two 68 TW Alexander Drive
Entity Address, City or Town Research Triangle Park
Entity Address, State or Province NC
Entity Address, Postal Zip Code 27709
City Area Code 919
Local Phone Number 636-4530
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security Common
Trading Symbol FENC
Security Exchange Name NASDAQ
Entity Emerging Growth Company false