Document and Entity Information - shares
6 Months Ended
Jun. 30, 2019
Aug. 07, 2019
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Trading Symbol ICON  
Entity Registrant Name ICONIX BRAND GROUP, INC.  
Entity Central Index Key 0000857737  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Current Reporting Status Yes  
Entity Shell Company false  
Entity Emerging Growth Company false  
Entity File Number 1-10593  
Entity Tax Identification Number 112481903  
Entity Address, Address Line One 1450 Broadway  
Entity Address, City or Town New York  
Entity Address, State or Province NY  
Entity Address, Postal Zip Code 10018  
City Area Code 212  
Local Phone Number 730-0030  
Entity Common Stock, Shares Outstanding   11,630,515