Document and Entity Information
12 Months Ended
Dec. 31, 2017
Document and Entity Information [Abstract]  
Entity Registrant Name Forward Pharma A/S
Entity Central Index Key 0001604924
Document Type 20-F
Document Period End Date Dec. 31, 2017
Amendment Flag false
Current Fiscal Year End Date --12-31
Entity Well-known Seasoned Issuer No
Entity Voluntary Filers No
Entity Current Reporting Status Yes
Entity Filer Category Accelerated Filer
Entity Common Stock, Shares Outstanding 94,367,998
Document Fiscal Year Focus 2017
Document Fiscal Period Focus FY