v3.10.0.1
Document and Entity Information
12 Months Ended
Dec. 31, 2018
Document - Document and Entity Information [Abstract]  
Document Type 6-K
Amendment Flag false
Document Period End Date Dec. 31, 2018
Document Fiscal Year Focus 2017
Document Fiscal Period Focus FY
Trading Symbol MRUS
Entity Registrant Name Merus N.V.
Entity Central Index Key 0001651311
Current Fiscal Year End Date --12-31